Bulletin STATE OF ILLINOIS DwiGHT H. Green, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Frank. G. Thompson, Director NATURAL HISTORY SURVEY DIVISION Theodore H. Prison, Chief Volume 22 B U L L E TI N Article 2 Studies of North American Plecoptera With Special Reference to the Fauna of Illinois T. H. PRISON Primed by Authority of the State oj Illinois URBAN A, ILLINOIS September 1942 STATE OF ILLINOIS DwiGHT H. Green, Governor DF.PAR'rMKNT OF RKGISTRATION AND FDUCATION Frank G. Thompson, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Frank G. Thompson, Chairman William Trelease, D.Sc, LL.D., Biology Arthur Cutts Willard, D.Eng., LL.D., Ezra J. Kraus, Ph.D., D.Sc, Forestry President oj the University oj Illinois L. R. HowsoN, B.S.C.E., C.E., £«^/««nw^. Edson S. Bastin, Ph.D., Geology Roger Adams, Ph.D., D.Sc, Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois Scientific and Technical Staff Theodore H. Prison, Ph.D., Chief Section of Economic Entomology W. P. Flint, B.S., Chief Entomologist C. C. CoMPTON, Ph.D., Associate Ento- mologist M. D. Farrar, Ph.D., Research Ento- mologist J. H. Bigger, M.S., Associate Entomolo- gist S. C. Chandler, B.S., Southern Field Entomologist James \V. Apple, M.S., Northern Field Entomologist B. G. Berger, M.A., Assistant Ento- mologist H. B. Petty, Jr., B.A., Assistant, Ento- mology Extension J. E. Porter, B.A., Entomological Assist- ant C. J. Weinman, Ph.D., Research Fellow in Entomology George F. Ludvik, B.A., Research Fellow in Entomology J. M. Magner, B.A., Junior Entomolo- gist (U.S.B.E.P.^. and Commodity Credit Corporation, cooperating) Section of Aquatic Biology David H. Thompson, Ph.D., Zoologist George W. Bennett, Ph.D., Limnolo- gist D. F. Hansen, Ph.D., Assistant Zoologist Bruno Limbach, M.S., Zoological Assist- ant Section of Game Research and Manage- ment R. E. Yeatter, Ph.D., Game Specialist Section of Wildlife Experimental Areas Arthur S. Hawkins, M.S., Game Tech- nician (On leave) F. C. Bellrose, Jr., B.S., Assistant Game Technician J. B. Low, Ph.D., Assistant Game Tech- nician W. H. Elder, Ph.D., Assistant Game Technician Cooperative Wildlife Restoration Pro- gram {State Department oJ Conservation and U. S. Fish and IVildlife Service) Harry G. Anderson, M.A., Junior Bi- ologist L. G. Brown, B.S., Junior Biologist R. E. Hesselschwerdt, B.A., Junior Biologist C. S. Spooner, Jr., M.F., Junior Biolo- gist Section of Applied Botany and Plant Pathology L. R. Tehon, Ph.D., Botanist D. B. Creager, Ph.D., Research Patholo- gist J. C. Carter, Ph.D., Assistant Botanist G. H. BoEWE, M.S., Field Botanist Section of Publications James S. Ayars, B.S., Technical Editor Consultant: Herpetology, Howard K. Gloyd, Ph.D., Director of the Museum, Chicago Academy of Sciences This paper ia a contributionfrom the Section of Insect Stirvey. (22821—1200—4-42) Section of Insect Survey jolo-H. H. Ross, Ph.D., Systematic Entor gist Carl O. Mohr, Ph.D., Associate Ento- mologist, Artist B. D. Burks, Ph.D., Assistant Entomolo- gist (On leave) G. T. Riegel, M.S., Entomological Assist- ant Kathryn M. Sommerman, M.S., Artist, Entomological Assistant Section of Forestry James E. Davis, M.F., Extension Forester Lee E. Yeager, Ph.D., Forester CONTENTS Page Acknowledgments 236 Disposition of Materiai 236 Arrangement of Subject Matter 236 Revised Classification 237 Revised Key to Families 238 Revised List of Illinois Species 240 Pteronarcidae 242 Peltoperlidae 245 Taeniopterygidae 247 Leuctridae 256 Nemouridae 260 Capniidae 262 Perlidae 271 Perlodidae 287 Isoperlidae 311 Chloroperlidae 337 Literature Cited 348 Index 351 i 0) 'o >.•£ «1 "" B u O O uW D .5 C 3 «n B U .2 13 'iM n «-n -o « jj 6 S = E Studies of North American Plecoptera T. H. PRISON With Special Reference to the Fauna of IlHnois THIS paper is a result of the contin- uance of studies of the stonefly fauna of Illinois started in 1926 and expanded within more recent years to include the fauna of North America. Three previous papers of mine have dealt entirely or in part with Illinois material of these aquatic insects ; the first dealing with the fall and winter species only (1929), the second with all the then known Illinois species (1935rt') and the third with additional information and re- cordings of species (1937). In 1937 the Illinois list of stoneflies stood at 38 species plus a questionable identification of a capniid female and the nymph of a species of Isoperla not place- able to species. Studies of Illinois material since 1937 have revealed the identity of the capniid adult and the Isoperla nymph, and added nine additional species to the Illinois list. Besides the study of Illinois Plecoptera, work has been in progress on the stonefly fauna of North America in general as a result of the availability of a large amount of adult and nymphal material submitted for identification by others or directly secured on collecting trips made by various members of the Illinois Natural History Survey staf¥. The Great Smoky Moun- tains National Park region and the states of Wisconsin and Michigan have been par- ticularly singled out for collecting trips because of their nearness to Urbana, 111., and the occurrence in them of numerous species not found in Illinois which are fairly representative of more northern and eastern sections of the United States and Canada. Numerous other collecting trips producing much material, trips often coupled with vacations or other duties, have been made by various staff members to almost all parts of the United States, with the exception of the southwestern states, and to southern Canada. In addi- tion to collection of adult and nymphal stonefly material in quantity, considerable attention always has been given on these trips to the taking of mating pairs and the rearing of adults from nymphs. Some of the rearing of adults from nymphs has been done at the point of collection by the use of special rearing cages and by working at night to secure adults emerging from nymphs. Other nymphal material has been transported to Urbana from distant locali- ties and then reared. Another phase of activity in connection with the Survey's study of the stonefly fauna of North America has been the care- ful examination of existing types. The collections of the Museum of Comparative Zoology, Cambridge, Mass., and of Cor- nell University, Ithaca, N. Y., in addition to the Illinois Natural History Survey collection, are particularly rich in typic specimens of Plecoptera, and all of the North American types in these collections have been critically studied upon several occasions. The writer has also been privi- leged to study most of the other types of North American Plecoptera scattered here and there in various collections throughout the country. The result of all this collecting, rearing, identification of material and study of types has naturally yielded much new in- formation regarding the association of nymphs with adults, the distribution of [235] 236 Illinois Natural History Survey Bulletin J'ol. 22, Art. 2 numerous species, the synonymy of certain species with others and the discovery of new species. In the present paper are the most important of these findings, with special emphasis upon a complete account of the fauna of Illinois. Acknowledgments 1 am indebted to many individuals and institutions for the donation or loan of material upon which this paper in part is based. Specimens of special importance have been donated or loaned by the follovv- injj:: Nathan Banks and F. M. Carpenter, -Museum of Comparative Zoology, Cam- bridge, Mass. ; J. Chester Bradley, C. McC. Alottley, J. G. Needham and Henry Dietrich, Cornell University, Itha- ca, N. Y.; Gordon B. Castle, Montana State University, Missoula, Mont.; A. C. Cole, Jr., University of Tennessee, Knox- \ille, Tenn. ; E. T. Cresson, Jr., Academy of Natural Sciences of Philadelphia, Phil- adelphia, Pa. ; K. C. Emerson, Oklahoma -Agricultural and Mechanical College, Stillwater, Okla. ; P. W. Fattig, Emory University, Atlanta, Ga. ; A. B. Gurney, U. S. Bureau of Entomology and Plant Quarantine, Washington, D, C. ; John F. Hans(jn, Massachusetts State College, Amherst, Mass.; P. H. Harden, Univer- sity of Minnesota, St. Paul, Minn.; Thel- ma Howell, Wesleyan College, Macon, Ga. ; P. J. Jennings, Brooklyn, N. Y. ; Stanley G. Jewett, Jr., Portland, Ore. ; D. E. Kimmins, British Museum, London, England ; Trevor Kincaid and Melville H, Hatch, University of Washington, Seattle, Wash.; Willis King, National Park Service, Gatlinburg, Tenn. ; G. F, Knowltoii, Agricultural Experiment Sta- tion, Logan, Utah; Mitsuko Kohno, Wa- kamatsu, Japan; J. W. Leonard, Institute for Fisheries Research, University of Michigan, Ann Arbor, Mich.; F. Earle Lyman, University of Michigan, Ann Arbor, Mich,; C. E. Mickel, University of Minnesota, St. Paul, Minn.; D. C. Mote and R. L. Post, Oregon State Agri- cultural College, Corvallis, Ore.; Ferris Neave, Pacific Biological Station, Nanai- mo, B. C, Canada; A. Colin Nicol, Uni- versity of Western Ontario, London, Ont., Canada; W. E. Ricker, Indiana University, Bloomington, Ind. ; H. G. Rodeck, University of Colorado, Boulder, Colo.; W. M. Sprules, University of Toronto, Toronto, Ont., Canada; W. C. Stehr, Ohio University, Athens, Ohio; M. C. Tanner, Ogden, Utah. H. H. Ross, B. D. Burks, G. T. Riegel and K. M. Sommerman, all staff members of the Insect Survey Section of the Illinois Natural History Survey, have greatly aided the preparation of this re- port by the collection of material, sorting and labeling of material and in numerous other ways. J. S. Ayars, Editor of the Survey, has materially assisted with the final reading, preparation and styling of this article. I am particularly indebted, however, to C. O. Mohr, Associate Entomologist with the Survey, for almost all the splendid drawings which illustrate this article. Good drawings of the important structural details of the adult and nymphal stoneflies and dorsal views of the nymphs are, in certain respects, better for identification purposes than are word descriptions. Be- cause of the excellent quality of these drawings, I have leaned heavily upon them in the writing of the descriptions. Disposition of Material All holotypes, allotypes and some of the paratypes of the species described as new in this article are deposited in the insect collection of the Illinois Natural History Survey at Urbana. Paratypes of some of the species are deposited elsewhere, as indi- cated in the typic records. Much of the material listed in this paper is in the collection of the Illinois Natural History Survey. In some, but not all, instances in which material is in collections other than that of the Survey that fact is indicated, the following ab- breviations being used for institutional col- lections. M.C.Z.—Museum of Comparative Zool- ogy of Harvard College, Cambridge, Mass. C.U.—Cornell University, Ithaca, N. Y. A.N.S.—Academy of Natural Sciences of Philadelphia, Philadelphia, Pa. Arrangement of Subject Matter In order to prevent treating various genera in two separate portions of this article, I have interwoven the subject September, 1942 Frisox : North American Plecoptera 237 matter pertaining especially to Illinois with that relating to the North American fauna as a whole. As in my paper dealing with the stoneflies of Illinois as a unit (1935a), I have followed a presentation order beginning with the Pteronarcidae and ending with Chloroperlidae. Revised Classification In my paper dealing with the stoneflies of Illinois (1935«), I gave a discussion of the classification then proposed for the Plecoptera of North America, together with an outline showing the relationships of the various groups as I then accepted them. As might be expected in the devel- opment of a classification of a neglected order of insects, the study of extensive material since 1935, particularly from western states, has caused some modifica- tions of my former views. My present ideas regarding the classifi- cation of the North American Plecoptera down to generic groups are represented by the outline below. This outline represents changes in my 1935 classification as follows: (1) reduc- tion of genera in the family Taeniop- terygidae to Taeniopteryx and Brachyp- tera, (2) removal of Eucapnopsis from the Leuctridae and its placement in the Cap- niidae, (3) addition to the Capniidae of the recently described genera of Isocapnia REVISED CLASSIFICATION OF THE PLECOPTERA OF NORTH AMERICA Pi; w H o u w HOLOGNATHA FILIPALPIA SYSTELLOGNATHA, SUBULIPALPIA or SETIPALPIA PTERONARCIDAE j Pteronarcys \ rteronarcella PELTOPERLIDAE [Peltoperla TAENIOPTERYGIDAE|J^^"^°p*,^'"^^ ( Bracnyptera NEMOURIDAE jNemoura LEUCTRIDAE. CAPNIIDAE PERLIDAE PERLODIDAE ISOPERLIDAE Isoperla Leuctra Megaleuctra Perlomyia Capnia Allocapnia Capnura Eucapnopsis Isocapnia Nemocapnia Atoperla Perlinella Neoperia Perlesta Acroneuria Neophasganophora Togoperla Claassenia Perlodes Oroperla Isogenus Hydroperla Dictyopterygella ^Diploperla /l CHLOROPERLIDAE I f Chloroperla I Hastaperia ] Alloperla Paraperia Kathroperia 238 Illinois Natural History Survey Bulletin I'ol. 22, Art. 2 and Semocapnia, (4) addition of Claas- sen'ui to the Perlidae. (5) addition of Dic- tyopitrygella to the Pcrhididae, (6) the recot;nition of Diphperla as the ^jcneric name for a K^^'UP ^^ species formerly for the ini)St part phiced in Ptrlu {s.l.), and its phxcement in the family of Perlodidae, (7) erection of a new family, the Isoper- lidae, for the genus Isoperla, which I formerly placed in the Chloroperlidae. (S) recognition of Oroperla as a genus of Perlodidae and (9) removal of Isoperla from Chloroperlidae and the addition to this family of Hastapfrla. Some of the now accepted genera repre- sent rather homogeneous groups of species, whereas other genera are quite hetero- geneous and may contain several more or less minor complexes. Acceptance of these minor complexes within the larger generic units as suhgenera will serve most nomen- clatorial and classificatory needs. For in- stance, Brachypiera represents a genus containing several smaller complexes, most of which (Nephopteryx, Obipteryx, Oem- opteryx, Rhabdiopteryx, Strophopteryx, etc.) have already been named and some- times considered as genera. No phylo- genetic relationships are lost or obscured by use of subgeneric names for such smaller complexes as Oemopteryx, for example, and the treatment of general entomological literature is often improved. The same applies to such genera as A'^- ttioura and Perlodes. Isoperla {s.l.), as I now recognize it, contains several sub- genera, some named and others unnamed. Almost any genus containing a number of species can be broken into finer subgeneric groups or complexes, but it is not the pur- pose of this article to go into detail con- cerning such classifications. Revisional papers dealing exhaustively with single families or genera are the best places for such lesser groupings to be defined and evaluated. The groupings of the above species are subject to the personal factor in evalua- tion by individual specialists, and, like an accordion, the skeletal organizational scheme can be pulled out or contracted. Some students of stoneflies prefer to group the nemourids, leuctrids, capniids and taeniopterygids as subfamilies of a single large family, the Nemouridae. I prefer, however, at least for the present and until the world fauna is better known, to con- sider them as separate families. The actual problems of ready identification and keying remain the same regardless of which policy is followed. Future and broader studies of the world stoneHy fauna will inevitably exert inHuences for some changes in exist- ing classificatory systems. REVISED KEY TO FAMILIES of the Plecoptera of North America {Figures illustrating almost all of the charac- ters used in these keys may be found in Frison 1935a) Adults 1. Anal area of forewings with two or more rows of crossveins ; basal ab- dominal sternites with remnants of nymphal gills Pteronarcidae Anal area of forewings entirely without crossveins or with but one row ; basal abdominal segments without remnants of nymphal gills 2 2. Cerci short, not longer than greatest width of the pronotum 3 Cerci long, much longer than greatest width of the pronotum 7 3. Forewings with numerous costal cross- veins; the pronotum, as viewed from the side, lies at a downward sloping angle to the otherwise general hori- zontal plane of the mesothorax and metathorax ; some species with gill remnants at least on sides of meso- thorax and metathorax above bases of legs Peltoperlidae Forewings with no or few costal cross- veins; the pronotum, as viewed from the side, lies in the same general hori- zontal plane as the mesothorax and metathorax; without any gill remnants on sides of mesothorax and metathorax above bases of legs 4 4. Second tarsal segment about as long as other tarsal segments Taeniopterygidae Second tarsal segment much shorter than other tarsal segments 5 5. Cerci with five or six segments Capniidae {Eucapnopsis only) Cerci one segmented 6 6. Apical marginal space beyond tip of sub- costa with an oblique crossvein ; some species with gill remnants in cervical region Nemouridae Apical marginal space beyond tip of sub- costa without oblique crossvein ; no gill remnants ever present in cervical re- gion Leuctridae 7. First tarsal segment long, about as long as the third tarsal segment; remnants of thoracic or submental gills never present; forewing with no or few median and cubital crossveins; fe- males with a narrow or broad, pale, weakly sclerotized, median, longitudi- nal band on basal abdominal tergites distinctly contrasting with strongly sclerotized lateral margins; labium September, 1942 Prison : North American Pi.ecoptera 239 with paraglossae and glossae extend- ing forward about the same distance and arranged alongside of one another in same horizontal plane (Filipalpia type) Capniidae First tarsal segment short, much shorter than third tarsal segment; remnants of thoracic or submental gills present or absent; forewing with from several to many median and cubital cross- veins; females without a weakly scle- rotized longitudinal band on basal ab- • dominal tergites contrasting with strongly sclerotized lateral margins; labium with paraglossae extending forward beyond glossae and so dom- inating glossae that the latter are much reduced (Subulipalpia type) 8 8. Remnants of branched filamentous gills on sides or venter of thorax, in posi- tion corresponding to location of branched filamentous gills in nymphs Perlidae No remnants of nymphal branched fila- mentous gills on sides or venter of thorax, or if gill remnants are present they are single, not branched, finger- like processes (some Perlodidae) 9 9. Remnant of finger-like gills located near each side of outer basal corner of sub- mentum Perlodidae {Perlodes, Isogcntu and Hydroperla) No remnant of finger-like gills located near each side of outer basal corner of submentum 10 10. Anal lobe of hindwing always present and large; anal lobe with 5 to 10 dis- tinct veins, exclusive of first anal vein, reaching margin of wing; males with lobe on posterior margin of seventh or eighth, or sometimes both seventh and eighth, ventral abdominal segments except for Dictyopterygella 11 Anal lobe of hindwing usually present, but sometimes small and in Hastaperla lacking; anal lobe usually with but two to three distinct veins exclusive of first anal vein, except Kathroperla which may have six or seven, reach- ing margin of wing; males without a lobe on posterior margin of either sev- enth or eighth ventral abdominal seg- ments Chloroperlidae 11. Males with lobe on posterior margin of seventh abdominal sternite, except in Dictyopterygella where all lobes are lacking and in Diploperla luctuosa which has lobe on eighth abdominal sternite; males with tenth abdominal tergite usually distinctly cleft, or if not distinctly cleft with subanal lobes projecting backward {Dictyopterygel- la) or with special terminal dorsal abdominal structures {Diploperla luc- tuosa, D. duplicata and D. bilohata) ; radial sector of forewing with from two to five branches, usually with three or more; subgenital plate of fe- male usually well developed, large and frequently covering most of eighth abdominal sternite Perlodidae {Dictyopterygella and Diploperla) Males without a lobe on posterior mar- gin of seventh ventral abdominal seg- ment but with such a lobe varying in size from small to large, always on eighth abdominal sternite ; males with tenth abdominal tergite never distinct- ly cleft; radial sector of forewing with from two to four branches, but usually with two ; subgenital plate of female sometimes not developed, and when present usually not covering most of the eighth abdominal sternite Isoperlidae Nymphs 1. Gills present on some of the ventral basal abdominal segments Pteronarcidae Gills absent on all ventral abdominal segments 2 2. Venter of thorax covered with large, overlapping, shieldlike plates Peltoperlidae Venter of thorax without distinct, large, overlapping, shieldlike plates 3 3. Labium with paraglossae and glossae extending forward about the same distance and side by side in the same horizontal plane 4 Labium with paraglossae extending for- ward much farther than the glossae, the latter deeply inset below and be- tween the paraglossae so as to appear almost as basal segments of them .7 +. Second tarsal segment approximately as long as or longer than the first seg- ment Taeniopterygidae Second tarsal segment shorter than the first 5 5. Small and robust nymphs, hairy; hind- wing pads extending considerably out- ward from the body at an angle; gills present or absent in ventral cervical region Nemouridae Small and slender nymphs; hairs few, fine or lacking; hindwing pads lying about parallel to longitudinal axis of body; no branched cervical gills ... 6 6. Lateral margins of abdominal segments somewhat rounded, segments widest at posterior margin and narrower to- ward base; hindwing pads with anal lobe or area extending far beyond middle of wing pad; forewing pads of males sometimes entirely lacking; last abdominal segment in males some- times with a conical projection Capniidae Lateral margins of abdominal segments almost straight, abdomen appearing more cylindrical; each hindwing pad with anal lobe or area small and not extending much beyond middle of wing pad ; forewing pads of males always present; last abdominal segment in males without a conical projection Leuctridae 7. Branched filamentous gills on sides and venter of thorax Perlidae Without branched filamentous gills on sides or venter of thorax 8 8. With a small membranous finger-like 240 Illixois Natural History Survey Bulletin lol. 22, Art. 2 gill located near each side of outer basal angle of submetitum Perlodidae yPfrloJfS, Isugrnus and Hydroperla) Without such gill on submentuin 9 9. Lateral margins of forewing pads ap- proximately straight or in line with longitudinal body axis; tip of lacinia with one or more teeth; diameter of fourth segment of maxillary palpus not much greater than base of hfth segment ; nymphs frequently with a conspicuous color pattern on dorsum of abdomen 10 Lateral margins of forewing pams of dorsatd. Klapaleic (1907) has shown that insignis is the same as regalis, and rigalis is a syn- onvni of dorsata, as a result of Smith's interpretation of Say's species. Ricker (1938) further confirms synonymy of in- signis with dorsata based upon study of the type of the former. In 1939, I studied the specimens in the Pr()\ ancher collection now in the Provin- cial Museum, Quebec, Canada, in hopes of definitely locating: types of rectus and fldvicarnis. In this collection I found one female and one male Pteronarcys associat- ed with the label of "P. regalis," and both are specimens of dorsata as I now recog- nize this species. Another female Pteron- arcys standing associated with the name ''rectus'' may be a type, and it also is dorsata. All specimens of Pteronarcys now in the Provancher cf)llection tend to confirm the correctness of placing these names rectus and flai'icornis in the synony- my of dorsata as done by Smith (1917). It should be mentioned here that Hagen's 1861 record for proteus and his 1873 record for nobilis should be placed in the bibliography of dorsata since Hagen in 1873 states that the specimens recorded by him in 1861 as proteus are regalis (= dorsata). Smith (1917) thus erred in placing Hagen's (1861) reference to proteus under proteus when it should go under dorsata. Also, Klapalek's (1907) reference to nobilis should be placed in the synonymy of dorsata and not under pic- tet ii (= nobilis) as done by Smith. As mentioned in an earlier paragraph, I am placing regalis in the synonymy of dorsata because of reared females from the same locality which show all stages be- tween having a straight posterior margin of the eighth abdominal sternite and hav- ing two conspicuous nipple-like processes. Hagen's (1873) report seems to be quite definite in regard to regalis having these nipple-like processes. Pteronarcys pictetii Hagen Pteronarcys pictetii Hagen (1873, p. 286). Original description, $, $. Pteronarcys regalis Hagen (1861, p. 15). New synonymy for $ . Pteronarcys nobilis Smith (1917, p. 448). New synonymy. Pteronarcys nobilis Needham & Claassen (1925, p. 36). New synonymy. Pteronarcys nobilis Prison (1935rt, p. 336). New synonymy. Under the discussion of dorsata (Say) I have shown that nobilis Hagen is the species called dorsata by Smith (1917), and that regalis Newman (1838c/) is a variant of dorsata. The types of pictetii are now in the Museum of Comparative Zoology, associ- ated with the type number "242." The female has labels associated with it as fol- lows : "Philadelphia— Winthem — Ha- gen." The male has associated with it the following data : "Meadville—Pa.— B. P. Mann." In view of the fact that the male type is the species dorsata, 1 hereby desig- nate the female type as the lectotype to govern the use of the name pictetii. A study of these types reveals that pictetii is the species called nobilis by Smith and was so synonymized by her. However, since Smith's concept of nobilis was in error, the name of pictetii, by selec- tion of typic female as lectotype, is the first name available to be used for the species called nobilis by Smith (1917), Needham & Claassen (1925) and Prison (1934 and 1935fl). Hagen's (1873) paper clearly corrected his earlier mistakes of 1861 regarding Pteronarcys, but he had no means of knowing that his nobilis and regalis would be found to intergrade and that dorsata would later be considered a species of Pteronarcys having name priority over both nobilis and regalis. I have been unable thus far to find definite workable characters for separating the nymphs of dorsata and pictetii. At one time I thought that more distinctive strip- ing of the nymphal abdomens indicated dorsata, but rearings have not confirmed this view, and the character of the water seems to have a marked influence upon the appearance of the nymphs. Mature female nymphs of pictetii can often be identified because of a strong indication of the in- cised posterior margin in the middle of the eighth abdominal sternite. Ricker (1938), in his remarks regard- ing Pteronarcys pictetii, implies that the type of pictetii is a specimen called proteus September, 1942 Frison: North American Plecoptera 245 by Pictet (1841) and is in the Zoological Museum, Berlin, Germany. Pictet's speci- men may be in the Zoological Museum in Berlin, but the types of pictetii are in the Museum of Comparative Zoology, as al- ready stated. Pteronarcys species In New Brunswick in 1939, a series of nymphs of Pteronarcys was taken which cannot be reliably assigned to any species known at this time. Since then a similar nymph has been collected in Connecticut. The nymph, fig. 2, because of lateral pro- jections on the sides of the first eight ab- dominal segments, is suggestive of the nymph at present associated with the spe- cies biloba Newman and proteus New- man. Of these two species it most closely resembles the nymph now assigned to bilo- ba because of the more prominent lateral lobes and the more sharply angled anterior corners of the pronotum. It differs from biloba, however, in that the lateral ab- dominal projections are much more devel- oped except on the first and eighth seg- ments, that there is a very prominent pro- jection on each side of the mesonotal wing pad, and that the projections at the corner angles of the pronotum are abnormally prominent. There is considerable question as yet regarding the true status of Pteronarcys comstocki Smith, and it is possible that the nymph now illustrated should be asso- ciated with this name. Reared material is needed to settle this and other points in- volved with the correct determination of several species of Pteronarcys. Data associated with these specimens are as follows. Connecticut.—Mount Carmel, Mill River, Sleeping Giant State Park: Oct. 14, 1941, K. M. Sommerman, 1 nymph. New Brunswick.—Penobsquis, crawling on rocks in small clear stream: Aug. 20, 1939, T. H. Frison & T. H. Frison, Jr., 18 nymphs. PELTOPERLIDAE This family is exceedingly interesting to the student of stoneflies because of its many unique features, including the strik- ingly roachlike appearance of the nymphs. Fig. 2.—Nymph of Pteronarcys species. Fig. 3.—Nymph of Peltoperla brevis. 246 Illinois Natural History Survey Bulletin !'ol. 22, Art. 2 Few recorils of the various dfscnbeil spe- cies occur ill literature, aiul the general taxonomy of the ^r^'np '^ ^:ir from satis- factor\ because of the lack of reared ma- HEAD AND THORACIC STERNITES Fij*. 4. — Peltoperla brev'is. terial and series of associated males and females, and because of certain weaknesses in existing specific descriptions. The character, number and location of the gills in the nMiiphs, and remnants of these in the adults, are certain to prove of great value in future work of identifica- tion. Claassen (1931) has given a good description of Peltoperla nrcuata Need- ham nymphs based upon reared material. This nymph has five pairs of filamentous gills, one pair each side near upper point of attachment of each mesothoracic leg, one pair each side near upper point of attachment of each metathoracic leg, and one pair on the underside of the meta- sternum. Nymphs in the Illinois Natural History Survey collection which certainly belong to P. brevis (Banks), fig. 3, have six pairs of gills, one pair near upper point of attachment of each leg and none be- neath the metasternum, fig. 4. These difierences in number and arrangement of gills indicate the taxonomic value of these characters, and they need to be carefully observed in all species. Dorsal view of the n>iiiph is illustrated in fig. 3. As in other adults whose nymphs have gills, the adults of Peltoperla show gill remnants when examined closely. I have noted, however, that adults of Peltoperla have membranous filaments on the dorsal thoracic segments which cannot be associ- ated with gills in the nymphs. These false gill-like appendages appear to be rem- nants of membranous tissue, an appearance occasioned by the peculiar shieldlike tho- racic segments of the nymphs. Peltoperla arcuata Needham Peltoperla arcuata Needham (1905, p. 108). Original description, $. Peltoperla arcuata Needham & Claassen (1925, p. 170). Description, $. This species was originally described from a female; the description of the male appeared later. Since the description of the male of this species by Needham & Claassen (1925) does not mention the peculiar shape of the anal cerci, I present three illustrations, fig. 5, which show their shape. These illustrations are based upon a specimen from Ithaca, N. Y., in the Cornell University collection, recorded by Needham & Claassen (1925). The figure presented by these authors for the male cf Abdominal segments Fig. 5. — Peltoperla arcuata. September, 1942 P^rison: North American Plecoptera 247 gives but slight indication of the manner in which the anal cerci bend inward near their bases, and, without mention of this unusual character in the text, its signifi- cance is lost. Peltoperla zipha new species Male.—Body, legs and cerci pale yel- lowish brown, with dorsum of head and thorax darker brown ; with basal segments of antennae concolorous with head and with apical segments darker. Compound eyes and ocelli black and contrasting with head. Head through compound eyes not so wide as anterior margin of pronotum, with posterior margin of compound eyes touch- ing anterior margin of prothorax. Two lateral ocelli present, anterior or median ocellus lacking or not visible ; lateral ocelli d" Abdominal sternites d" Abdominal tercites ' Abdominal segments Fig. 6. — Peltoperla zipha. about twice as far apart as each is distant from adjacent compound eye. Pronotum much wider than long, an- terior corners angular and posterior cor- ners much rounded, raised rugosities on posterior two-thirds of area. Legs with third tarsal segments much longer than second and first tarsal segments combined, the first segment slightly longer than the second. Dorsum of abdomen without special structures through ninth tergite ; tenth tergite with anterior part forming a strongly sclerotized upraised ridge at- tached to a cleft, more membranous area from which the long, slender, pointed supra-anal process arises, fig. 6; two minute membranous lobes are adjacent to place where supra-anal process projects; ninth abdominal sternite with a broad, slightly elevated, weakly developed lobe in middle. Cerci straight, with about 14 segments. Wings extending far beyond tip of ab- domen and with venation as illustrated in fig. 6. The gill remnants are difficult to locate but there appear to be one on each side of the mesosternum and metasternum near point of articulation with leg and certainly one or more on each side near upper point of attachment of each mesothoracic and metathoracic leg. False gills are evident, one on each side, on the mesonotum and on the metanotum. Length to tip of wings 12 mm. ; length to tip of abdomen 8 mm. Holotype, male.—Tributary of Little River, Elkmont, Tenn.: May 14, 1939, T. H. Prison k H. H. Ross. This new species is quite different from any described species and is easily separated from arcuata Needham (Smith 1917) be- cause it lacks the small lobe at base of the ninth abdominal sternite and has straight anal cerci. It differs markedly from the male of comelia Needham & Smith and related forms in the shape of its supra- anal process. TAENIOPTERYGIDAE The generic classification of the Taeni- opterygidae presents several problems which are impossible to elucidate thor- oughly or unravel at this time. Studies of the North American species, adults and 248 li.i.iNois Natlrai. History Sl'rvi;v HLi.i.iiriN I ol. 22. Art. 2 nymphs have indicated that the species separate into two fundamentally different groups. These two groups were recognized in my studies of the Illinois species (l'^2'5, I^).^5^;) as the genera Tatninpttryx Pictet (1841) (= Siplu'loptcryx Klapalek V)()2) and Strophoptrryx Frison (192Q). Beginning with Klapalek. in 1%2, numer- ous generic names have been proposed for the reception of various species in this family. Since the world species break up into many small units, and each new spe- cies seems to present a new combination of the characters used as the basis for these genera, I am following the course, at least for the present, of accepting these names as subgenera and holding to a gener- ic division which presents more marked or fundamental differences in the nymphs as well as adults. The name of Taeniopteryx Pictet (1841) with its genotype of nebulosa (Linnaeus), as used by me in 1929, still holds for one of these basic genera, and the name Brachyptera Newport (1851) with its gen(Jtype of triidsciata (Pictet) is the first name available for the other. Strophopteryx Frison (1929) belongs as one of the subgenera of Brachyptera. In Taeniopteryx belong the species like rnaura (Pictet), which have nymphs with coxal gills, adult males with one-segmented cerci and a ninth abdominal sternite reaching only to tip of abdomen, and adult females with the subgenital plate poorly developed. In Brachyptera belong the species like fasciata ( Burmeister ), which have nymphs lacking coxal gills, adult males with sev- eral-segmented cerci and a ninth abdom- inal sternite recurved up about the tip of the abdomen, and adult females with the subgenital plate much produced. KP:V to GliNERA OF TAPlNIOPTERYdlDAE Adli.ts Males with one-segmented anal cerci, ninth abdominal sternite reaching only to tip of abdomen and not abruptly recurved upwards about tip of abdomen, forewings always normal; females with subgenital plate not or scarcely produced ; both sexes show coxal gill scars Taeniopteryx Males with several-segmented anal cerci, ninth abdominal sternite abruptly curved up about tip of the abdomen, forewings sometimes brachypterous ; females with a well-developed anrl protruding subgenital plate; both sexes without traces of coxal gill scars Brachyptera NV.MIMIS Coxal gills present and terminal abdominal structures suggestive of characters of adults Taeniopteryx Coxal gills absent and tenninal abdominal structures suggestive of characters of adults Brachyptera Taeniopteryx maura (Pictet) Simotira maura Pictet (1841, p. 361). Orig- inal description, $. Nemoitra nivalis Fitch (1847, p. 274). New synonymy. Taeniopteryx nivalis Frison (1929 and 1935rt, pp. 378 and 341, respectively). Descrip- tions and records. In my paper of 1929 1 stated that "it is likely nivalis and maura are the same spe- cies," and, again, in 1935 that "there is a strong probability that maura (Pictet) and nivalis (Fitch) are the same species ... in which case the former name would have priority." Since these earlier papers I have had occasion to determine many hundreds of specimens from all parts of the distribu- tional range of nivalis and maura, and I have come to the definite conclusion that nivalis should be regarded as a synonym of maura. In the past, maura and nivalis have been separable in the males only, and then on the basis of the presence or ab- sence of a toothlike projection on the lower surface of each femur. As first pointed out in 1929, I find in the males from the same locality that some have this toothlike projection and others do not ; in fact, speci- mens are not uncominon which have the tooth on one femur and lack it on the other. Another structural character of maura displaying great variation in size and shape is the lobe near the base of the ninth abdominal sternite. Coupled with the facts that two species of females can- not be detected and that differences in other characters known to be of great specific importance (such as the cerci, supra-anal process and subanal lobes) can- not be found, it no longer seems tenable to recognize maura and nivalis as two distinct species. Whether the name of maura is being correcth used can never be definitely settled because, as Ricker (1938) records, only parts of the type remain, and they are not the parts most needed to make ac- curate determinations of species belonging to this fainily. No specimens of the typic September, 1942 Prison: North American Plecoptera 249 series of nivalis are known to be in exist- ence. It seems that the best interests of nomenclature and taxonom\' will be served by using the name of nuiura for this spe- cies. It has been interesting to find, in a large series of specimens from Oregon, adult and nymphal specimens which I cannot satisfactorily separate from niaiira material taken in eastern North America (Frison 1942). Slight differences in wing color seem to exist, but characters of this nature are apt to be variable. Taeniopteryx maura is common in parts of Minnesota, and no doubt it will be found eventually in states or Canadian provinces east of Oregon and west of Minnesota. The species maura (^ nivalis and mau- ra) has been previously recorded from the District of Columbia, Illinois, Maine, Maryland, Massachusetts, New Hamp- shire, New York, North Carolina, Nova Scotia, Pennsylvania and Virginia. To this list I can now add the states of Con- necticut, Florida, Georgia, Indiana, Iowa, Kentucky, Michigan, Minnesota, Mis- souri, Ohio, Oklahoma, Oregon, Tennes- see, West Virginia and Wisconsin. Taeniopteryx parvula Banks Taeniopteryx parvula Banks (1918, p. 7). Original description, c^ . Taeniopteryx parvula Frison (1929, p. 383, and 1935rt, p. 345). Additional descriptions and records. The typic series of parvula consists of two males, No. 10,049, in the collection of the Museum of Comparative Zoology. One of these is from "Washington, D. C," and the other from "Peach Grove Aedeagus OOBSAL VIEW SUBANAL LOBE Lateral VIEW Dissection showing ventral view of male subanal lobes Fig. 7.— Taeniopteryx parvula. Hill, Va., Feb. 21, 1915," and I am selecting the latter as the lectotype. In view of the fact that there is another species of Taeniopteryx, described in this article as lita, very closely related to and apt to be confused with parvula, I wish to present drawings of the aedeagus, fig. 7, and of the subanal lobes, not previously illustrated. Drawings of other aspects of parvula are available for comparison in Frison 1935« (figs. 190, 214 and 223). It has been an interesting discovery to find that the aedeagus of parvula and of lita are very different, a discovery suggesting that this character merits study in the case of other species of this famih. Taeniopteryx lita new species Male.— In general similar to parvula Banks as redescribed by Needham & Claas- sen (1925). It differs from parvula as follows : The supra-anal process is much broader at tip, and the one-segmented cerci have a small finger-like process on upper surface, fig. 8 ; subanal lobes are prominent and lobate at tips, whereas in parvula these same lobes are less developed and terminate in a small pointed hook, fig. 7 ; ninth abdominal sternite with a membra- nous area on posterior median margin cov- ered and surrounded with long, fine setae, fig. 8 ; aedeagus in various views as in Wing venation as in fig. 8. Length to tip of wings 10 mm. Female.—Head, thorax, basal abdom- inal segments and appendages in general similar to those of male. Genital opening near middle of eighth abdominal sternite, not covered by a plate, sclerotized areas bordering opening larger, fig. 8, than in parvula (Frison 1935^, fig. 214). Holotype, male.—Elizabethtown, 111.: March 7, 1928, T. H. Frison & H. H. Ross. Allotype, female.—Same data as for holo- type. Paratypes. — Illinois. — Elizabethtown: Same data as for holotvpe, 3^. Golconda: March 17, 1932, H. H. Ross, H. Grayville, Wabash River: March 8, 1928, T. H. Frison & H. H. Ross, 7 i . Arkansas.—Brasfield, Cache River: April 16, 1939, H. H. & J. A. Ross, U. Indiana.—St. Anthony: Feb. 13, 1938, T. H. Frison & C. O. Mohr, H. Rogers, White River: March 14, 1936. T. H. Frison & H. H. Ross, A-i. WiNSLOW, Patoka River: Feb. 14, 1938. T. H. Frison & C. O. Mohr, 2i . Maryland.—Priests Bridge: Feb. 25, 1938, B. D. Burks, IS. 250 Illinois Natirai. History Survi-y Hui.letin I ol. 22, Art. 2 (TABOOMINAL TEROITES Dissection showing ventral view of male subanal lobes d" Abdominal SEGMENTS liji. 8.— Taeniopteryx it la. Mississippi.—Potts Camp: Feb. 17, 1941, T. H. Prison, 1^, 29. I his is a species apparently with a more southern distribution than parvula and easily apt to be confused with it. It is not unh'kcly that some of the records of Need- ham & Claassen (1925) for parvula per- tain to this new species. Illinois records of parvula from Elizabethtown (in part), Golconda and Grawille (in part) record- ed in my 1929 and 1935^/ papers belong to this species. Brachyptera fasciata (Hurmeister) SemhI'ts fasdata Burmeister (1839, p. 875). Original description. Strophnptrryx fasaala Prison (1929 and 1935rt, pp. 384 and 347, respectively). Addi- tional descriptions. In 1929 I proposed the generic name of Sfropliopteryx for the inclusion of fasciata, because fasciata possessed some characters which did not fit the various genera then in use for the Taeniopterygidae. Also, 1 wished to emphasize the marked funda- mental dilierences existing in both adults and nymphs between such Illinois stone- flies as the species then known as Taeniop- teryx nivalis (Fitch) and Seniblis fasciata. In my remarks in this article under the heading of Taeniopterygidae, I have stated my reasons for now recognizing but two genera in this family, Taeniopteryx and Brachyptera. This procedure reduces Sfropliopteryx to subgeneric status along with such names as Rhahdiopteryx Kla- palek and Oemopteryx Klapalek. While determining large series of fasci- ata, I have observed instances of variation. The most noticeable involves the occur- rence or non-occurrence of membranous SuBANAL LOBES d" Abdominal tergites Fig. 9. — Brachyptera fasciata. SuBANAL LOBES (JAbDOMINAL TERGITES Fig. 10. — Brachyptera fasciata. September, 1942 Prison : North American Plecoptera 251 lobes, one on each side, on the posterior margin of the ninth abdominal tergite in the males, fig. 9 ; in some males these lobes are present, whereas in manj' specimens they are lacking or relatively undeveloped, fig. 10. The subanal lobes of this species are asymmetrical, and in spite of their complexity I have failed to find marked differences in kind between these struc- tures in males with and in males without the lobes on the ninth abdominal tergites, figs. 9 and 10. This latter fact, plus fail- ure to find differences in the females and nymphs, has influenced my evaluation of the absence or presence of these lobes on ninth abdominal tergite as a non-specific character. Brachyptera glacialis (Newman) Nemoura (Brachyptera) glacialis Newman (1851, p. 451). Original description, 6, 9- Taeniopteryx (Uemopteryx) alex Hanson (1938, p. 79). New synonymy. Taeniopteryx glacialis Ricker (1938, p. 131). Notes regarding types. In the collection of the Museum of Comparative Zoology, there is a male of glacialis from "Hudson's Bay" which is undoubtedly the typic male specimen men- tioned by Ricker (1938) as having "been sent to the Museum of Comparative Zo- ology." Ricker (1938) selected lectotypic and lecto-allotypic specimens from the series of two male and three female types now in the British Museum. This species was entirely omitted by Needham & Claas- sen (1925) in their Monograph. I have studied in fluid the genitalic structures of the typic male in the Mu- seum of Comparative Zoology, paratypic specimens of Taeniopteryx (Oeinopteryx) alex and other specimens, and as a result 1 have come to the conclusion that alex is a synonym of glacialis. I can find no definite characters to separate them, and any differences observed can be ascribed to variation. Hanson described alex from specimens col- lected at Wells, Hamilton County, N. V. Records or specimens in the Illinois Natural History Survey collection or specimens I have determined for others are as follows. Connecticut.—Danielson: March 24, 1937, H. H. Ross, 56, 4?. Minnesota.—Lake County, Stewart River: March 26, 1938, R. H. Daggy & W. S. Chal- gren, 5 $ . Utah.—Myton: March 16-19, 1940, R.A.Z., 36, 5$. Brachyptera oregonensis (Needham & Claassen) Taeniopteryx oregonensis Needham & Claas- sen (1925, p. 248). Original description, 6- This species was originally described from males only, collected at Corvallis, Ore. Since the female has not been pre- viously described it seems desirable here to FijJ. 11.- Brachyptera oregonensis. Q Abdominal sternites illustrate the important features of the terminal abdominal sternites of a female, fig. 11, based upon a specimen collected at Dixon Creek, Corvallis, Ore., March 10, 1935, by R. E. Dimick. Since all other characters are approximately the same as those in the male, this illustration show- ing the shape of the subgenital plate will suffice for a description of this sex, and the specimen is designated at the allotype. A large number of specimens of oregonensis are now in the Illinois Natural History Survey collection, and I have determined many speci- mens for others. These records are too numer- ous to be given in detail here but come from the following localities in Oregon: Benton County, Canyonville, Clackamas County, Clat- skanie, Clatsop County, Columbia County, Cor- vallis, Crabtree, Forest CJrove, Hiilsboro, Leb- anon, Lewisburg, Oak Creek, Philomath, Polk County, Portland, Salem, Seaside, Warren and Wren. Brachyptera pacifica (Banks) Taeniopteryx pacifica Banks (1900, p. 244). Original description, 6, $• Taeniopteryx raynoria Frison (1942, p. 9). Recent synonymy. Taeniopteryx kincaidi Prison (1942, p. 9). Recent synonymy. In a recent publication (1942), I treat- ed raynoria Claassen {\9Z1 h) and kin- caidi Hoppe ( 1938) as synonyms of pacifi- ca. Additional comments regarding the types involved and the synonymy adopted are herewith presented. 252 Illinois Natlral History Survky Blllktix lot. 22. An. 2 Thf t\pt's of ptiiiluti arc in the coUec- ti«)ii ot the Museum of Comparative Zo- olojiy and bear the t\pe number "11,304" and the locality of "Pullman, Washing- ton." In the typic series are three speci- mens, one male and two females. Throujih the kindness of Dr. Nathan Banks 1 was permitted to relax and study closely in riuid the jjenitalic characteristics of one male, and I herewith desij^nate this male specimen as the lectotype. The holotype, allotype and paratypes of kincauii were sent to me for study through the kindness of Professor Trevor Kincaid of the University of Washington, and the holotype and allotype of raynoria were studied through the courtesy of Professor j. Chester Hradle\ of Cornell University. I synonymi/.ed raynoria and kincaidi with paiifica in my most recent stonefly paper (1942) because of my belief that all observable difierences fall within the limits of specific variation and involve no marked differences in kind of structures. The differences observed included varia- tion in the size and shape of the rearward- pointing appendages on the tenth abdom- inal tergite and the lobes protruding up- ward from the bases of the cerci, as well as differences in pigmentation of the ab- dominal segments. It may be that some of these differences predominate in certain geographical areas, and such names as raynoria and kincaidi can be used in the future for geographical races or subspecies. For instance, the rearward-pointing lobes on the tenth abdominal tergite of the type of raynoria, which comes from "Yosemite, California," is larger than in many speci- mens 1 consider as pacifica in the Illinois Natural History Survey collection from Oregon, Washington and British Colum- bia. Claassen (lOJ?/*) gave an illustration of the lateral view of the terminal abdom- inal segments of his raynoria, and better to show its similarity with pacifica I include here a dorsal view of the terminal abdom- inal segments of the holotypic male, fig. 12, and a ventral view of the terminal ab- dominal segments of the allotypic female, fig. 12, which Claassen did not illustrate. Taeniopteryx kincaidi, from several lo- calities in Washington, was placed in the synonymy of pacifica ( Frison 1942) for the same general reasons as just given in the case of raynoria. In her key involving the separation of the species of Taeniop- teryx from Washington, Hoppe (1938) keys out pacifica from kincaidi on the basis of the presence of two raised rear- ward-pointing appendages on the tenth abdominal tergite of the male in pacifica and their lack in kincaidi. No good spe- cific characters for the separation of these $ Abdominal STCRNiTES cf Abdominal tergites Fig. 12.—Brachyptera pacifica. two species are given in the original de- scription of kincaidi. An examination of the males in the typic series of kincaidi reveals the presence of these lobes exactly as in pacifica. The statements in the key regarding "Hind margin of the tenth ter- gite extended rearward" undoubtedly re- fer to the ninth tergite, and this particular structure seems to vary considerably in specimens of pacifica. Taeniopteryx pallida (Banks 1902), de- scribed from "Little Beaver, Colo., July 18, 1898," is yet another species which must be considered in the final synonsmy of the pacifica complex. Although at the present time I cannot certainly separate the typic female of pallida from other females of the pacifica complex, I have hesitated to sink this name in synonymy because of lack of males associated with females which may be considered as pal- lida. There is a possibility that the male when fcund might be distinct enough to warrant specific recognition. On the other hand if the male that goes with pallida falls within the pacifica complex, then the name pallida will be antedated only by pacifica. It has been most interesting to discover that pacifica is not restricted to the west- ern states and that it occurs in cold rapid streams in the mountainous parts of Mary- land, New Hampshire, New York, North Carolina, Tennessee, V'irginia, and no September, 1942 Frison : North American Plecoptera 253 doubt other states. Critical comparative studies of eastern and western material have failed to reveal any significant char- acters for the separation of eastern speci- mens from western specimens. With re- spect to variation in the size of the lobes on the posterior margin of the tenth abdomi- nal tergite, the eastern specimens are of the small type. A similar instance of a species of taeniopterygid occurring in both eastern and western parts of the United States has been recorded for Tdeniopteryx inaurn ( Pictet ) under the name of nivalis (Fitch) by Frison (1042). Records for pacifica from eastern North America, based upon material in the Illinois Natural History Survey collection or examined by me, are as follows. Maryland.—Piney Grove: April 19, 1938, H. H. Ross, 1 £ . New Hampshire.—Mount Washington: Brook near Pinkham Notch Camp, June 22, 1941, Frison & Ross, IS , ? $. New York.—Mount Tremper, Esopus Creek: April 27, 1935, P. jeniiings, 1$. Phoenecia: May 5, 1940, P. Jennings, 1 .^ , 3 9. Schoharie: ex trout stomach, April, 1937, P. Jennings, 2 nymphs; May 5, 1937, P. Jen- nings, lo ; May 28, 1937, Flock, 1? ; April 16, 1938, P. Jennings, 1$, 29 ; ex trout stom- ach, April, 1940, P. Jennings, l£, 2$, 2 nymphs. North Carolina.—Blowing Rock: March 23, 1940, Frison, Mohr & Hawkins, 1$, 2 exuviae; near Grandfather Mountain, west of town, March 23, 1940, Frison, Mohr & Haw- kins, 3 nymphs. Willets: March 23, 1940, Frison, Mohr & Hawkins, IS, 2$. Tennessee.—Gatlinburg: March 24, 1940, Frison, Mohr & Hawkins, 4c5, 5 exuviae. Greenbrier Cove: March 15, 1938, 2,000 feet elevation, Smoky Mountains, A. C. Cole, 1 $ . Virginia.—Speedwell: March 22, 1940, Frison, Mohr & Hawkins, 19, 2 exuviae. Sperryville: March 17, 1940, Frison & Mohr, 29. Brachyptera vanduzee (Claassen) Taeniopteryx vanduzee Claassen (1937Z', p. 46). Original description, $. I have studied the type of this species in the collection of Cornell University, through the kindness of Professor J. Chester Bradley, and find vanduzee to be a distinct and valid species. It differs from all other western species of the genus in the presence of a lobe on the ninth ab- dominal sternite. The genitalic structures are complicated, and, since the illustration given by Claassen (1937) is rather in- distinct, I present fig. 13 of the type show- ing in greater detail important features of this species. Fig. 13.- Brachyptera vanduzee cf Abdominal sternh"-^ The type was collected at "Tahoe, Cali- fornia." Additional specimens of this spe- cies have not been seen or recorded by other entomologists. Brachyptera contorta (Needham & Claassen) Taeniopteryx contorta Needham & Claassen (1925, p. 242). Original description, S- This species has not been recorded in literature since it was described from a single male from "Jaffery, N. H., March 18, C. W. Johnson" in the collection of Cornell University. Since the female and nymph have not been described, I present brief descriptions of their most important characters as follows. Female.—In general similar to the male as described by Needham & Claassen (1925). Co.xae without small, round, membranous areas on ventral surfaces (evidence of lack of tracheal co.xal gills in nymph). Venation of wings as in fig. 14. Ninth abdominal sternite produced in- to broad, rounded plate shaped as in fig. 14. Allotype, female.—East Hampton, Lvman's Brook, Conn.: March 24, 1937, H. H." Ross. Taken at same time and place as males of the same species. 254 Illinois Natural History Survey Bulletin lol. 22. Art. 2 NvMPH.—In general similar to the nvmph of fasciata (Burmeister ) , as de- scribed by Prison (1929, p. 385). Differs Nymphal abdominal sternites Q Abdominal sternites Fig. 14. — Brachyptera inntorta. chiefly in that ninth abdominal sternite has a broad, platelike projection extending about to tip of abdomen, fig. 14, instead of a narrow, platelike projection. Nymphal specimens from same locality as allotyjie. Illinois Natural History Survey collection records are as follows. Connecticut.— li.xsT Hampton: Same data as for allotype, 26 , 1 $ , 16 nymphs. Virginia.—Standardsvili.e: March 21, 1940, T. H. Prison, C. O. Mohr & A. S. Hawkins, l(i, 79. Sperrvville: March 17, 1940, T. H. Prison, et al., 76, 3$, 3 nymphs. Brachyptera rossi new species Mali;.—General habitus similar to that of other species of Brachyptera. Head, thorax and abdomen mostly black with portions suli'used with reddish brown. An- tennae black, the segments longer than broad throughout length. Legs with tarsi, tibiae and apical third of each of the femora black ; basal two-thirds of each of the femora yellowish brown. No traces of membranous gill scars on coxae. Wings with veins black and membrane smoky, venation as in fig. 15. Apical abdominal segments intricately modified and presenting the distinctive characters, fig. 15, for this new species as folhjws: Ninth abdominal sternite greatly prolonged into a plate which extends back beyond the tip of abdomen, then bends upwards and is club headed at tip as viewed from the side, with a stout, sickle- shaped structure at tip as viewed from above, and near its base there is a prom- inent lobe ; tenth abdominal tergite bears two slender, pointed projections, directed backwards, on middle of posterior mar- gin ; cercus 5 or 6 segmented, with a plate- like lobe at its base above; supra-anal process a short, stout, pointed lobe; sub- anal lobes complicated, asymmetrical and, viewed from above, as in fig. 15. Length to tip of wings, 13 mm. Holotvpe, male. — Near Woodstock, Bog Brook, N. H.: June 21, 1941, T. H. Prison & H. H. Ross. I take great pleasure in naming this spe- cies for Dr. H. H. Ross, of the Illinois Natural History Survey staff, who has greatly assisted in many ways my studies of the North American Plecoptera. Five Brachyptera exuviae were found under a bridge near the place where the cf Abdominal segments Fi}*. 15. — Brachyptera rossi. September, 1942 Prison: North American Plecoptera 255 holotype was collected. The exuviae rep- resent both males and females, are very dark, lack a longitudinal pale stripe on ab- dominal tergites, lack coxal gills and, from shape of apical abdominal segments, un- doubtedly should be associated with rossi. The peculiar, pointed projections on the tenth abdominal tergite, combined with the lobe on the ninth abdominal sternite, readily separate the adult of this new spe- cies from adults of all previously described species. Brachyptera limata new species Male.—General habitus similar to that of other species of Brachyptera. Head, thorax and abdomen mostly yellowish c?Abdominal TERGITES Fig. 16. — Brachyptera limata. Fig. 17.—Nymph of Bracliyplcra limata. brown, antennae and parts of thorax dark brown. No traces of membranous gill scars on coxae. Wings stained with brown, venation as in fig. 16. Apical abdominal segments intricately modified and presenting the most distinc- tive characters for this new species, hg. 16, as follows: Ninth abdominal sternite greatly prolonged into a plate which ex- tends back beyond tip of abdomen, then bends upward, but becomes considerably narrowed at tip, without a lobe near base; tenth abdominal tergite without any pro- jections near base ; cerci several segmented, with a small globose lobe above base; supra-anal process short, somewhat re- J56 Iii.iNois Natirai. History Sir\j-v Hli.i.ktin lol. 22. Art. 2 curved up ami forward with tip forming a point ; subanal lobes complicated, asMii- inetrical and. as viewed from above, are as in fiji. lb. I^en^th to tip of winjjs 10 mm. Fh.male.— Head, thorax, basal abdom- inal segments and appendages in general similar to those of male. Genital t)pcning near middle of eighth abdominal sternite not covered by a plate. Ninth abdominal sternite prolonged to form plate reaching nearly to tip of abdomen and rounded at tip. fig. 16. Holotype, male.—Newfound Cjap near Gat- linbiirg, Little Pigeon River, Tenn.: Mav 14, 1939, r. H. Prison & H. H. Ross. Allotype, female.—Same data as for holo- type. Paratypes. — Tennessee.— Newfound Gap: Same data as for holotype, 22^, 78$. N^'.Mi'H.— In general similar to the n\mph of fasiiaia ( Burnieister ), as de- scribed byFrison (1929. p. 385). No longitudinal pale stripe on abdominal ter- gites, fig. 17. Platelike projection of ninth abdominal sternite somewhat broader than in fdsciata, and abdominal tergites uni- formly brownish. Nymphal and exu\ ial specimens with same data as for holotype. This new species presents many struc- tures which place it close to the western Brachypterti nigripetinis (Banks), from which it diliers. however, in shape of supra-anal process, in shape of lobes at base of each cercus, and by the much-narrowed tip of the ninth abdominal sternite. It differs froin li. pacifica (Banks), another western species, in lacking lobes at base of tenth abdominal tergite. b\ the much-nar- rowed tip of ninth abdominal sternite, and other characters. LEUGTRIDAE Leuctra Stephens At the time of the publication of The Stoneflies, or Plecoptera, of Illinois (Frison 1935rt), claasseni Frison (1929) was the only species of Leuctra known to occur in Illinois. Since then, intensive field work in exceedingly local, small and segregated habitats has revealed the pres- ence of two additional species. It becomes desirable, therefore, to record these new additions to the Illinois list, to illustrate the characters most useful in recognizing the three Illinois species and to present a ke\ for identif\ing them. KKV TO ILLINOIS SPECIES OF I.ElCTR.i ADl'LTS Males 1. Ninth abdominal tergite with a promi- nent, sharply outlined, deep, longitudi- nal cleft, fig. 18 claasseni Ninth abdominal tergite without such a cleft 2 2. Seventh abdominal tergite with a conspic- uous, rearward-pointing process, fig. 20 tenuis Seventh abdominal tergite without a spe- cial process, fig. 19 decepta Femai.es 1. Eighth abdominal sternite about as long as seventh, with posterior margin in middle indented so that sternite is bi- iobed 2 Eighth abdominal sternite much shorter than seventh, posterior margin not bi- lobed ; three small, separated, humplike areas on anterior margin, fig. 18 claasseni 2. Seventh and eighth abdominal sternites conspicuously fused ; cleft between lobes of posterior margin of eighth sternite wide and deep, sides and tips of lobes formed by a cleft more strongly and darkly sclerotized than rest of sternite, fig. 20 tenuis Seventh and eighth abdominal sternites indistinctly' or weakly fused ; cleft be- tween lobes of posterior margin of eighth sternite narrow, sternite almost uniformly sclerotized, fig. 19. decepta Hanson (1941) in a recent paper has separated Leuctra as previously used by ether North American workers into two genera, Leuctra Stephens and Faraleuctra Hanson. It is obvious to anyone who has closely studied a series of species of Leuctra {s.l.) that this genus contains some smaller coinplexes. Faraleuctra may be of generic rank, but, for the time being, pending a thorough revisional study of the Leuctridae, 1 prefer to recognize Fara- leuctra as a subgenus. If Faraleuctra is a valid genus, it is probable that other addi- tional generic names will be necessary. Faraleuctra is represented in Illinois by claasseni Frison. Leuctra claasseni Frison Leuctra claasseni Frison (1929, p. 404). Original description, i . Leuctra claasseni Frison (193 5fl, p. 355). Description and new records, 9- Fhe original description of this species was based solely upon Illinois specimens, September, 194-2 Frison : North American Plecoptera 257 and additional records of specimens from Missouri and Oklahoma were added in 1935. Since the Missouri record was based upon a nymph whose identity was assumed because of the presence of claas- serii in similar and adjacent territory in Illinois, a doubtful procedure in this genus w here nymphs are of homogeneous appear- ance, I am pleased to confirm the Missouri record from adult specimens and to add additional distributional records as fol- lows. Indiana.—Turkey Run State Park, Newby Gulch: May 12, 1933, T. H. Frison & C. O. Mohr, 1 nymph. Tributary of Sugar Creek, east of Turkey Run State Park: April 9, 1940, T. H. Frison & H. H. Ross, 116, 5$, 1 nymph. Missouri.—Southeast of Ei.lsinore: March 8, 1939, T. H. Frison & C. O. Mohr, IS (reared), 19,2 nymphs. Ohio.—Ash Cave: March 6, 1938, T. H. Frison, 1 i . New illustrations of the important male and female structures, fig. 18, are present- ed to aid with the separation from other Illinois species. Both the male and the female of this species are markedly differ- ent from decepta Claassen and tenuis (Pictet), the other two Illinois species of Abdominal tergites Abdominal sternites Leiictrti ; in fact, chiasscni is so distincti\e that it represents a subgroup or division among North American species of the genus, which Hanson (1941) has named Parnleiictro. Leuctra decepta Claassen Leiutra decepta Claassen (1923, p. 260). Original description, i, 9- Leuctra decepta Needham & Claassen (1925, p. 227). Additional record. Leuctra decepta Claassen (1931, p. 99). Nymphai description. Leuctra decepta was described from New York specimens and, since the orig- inal description was published, this species c? Abdominal sternites (? Abdominal tergites Abdominal segments 2 Subgenital plates ah*.' n^. 1.^.— Leuctra claasseni Fi.^. 19. — Leuctra decepta. has not been recorded from other states. The recent finding of this species in south- ern Illinois and other places indicates it is widely distributed in eastern North Amer- ica. Since this species was not known to occur in Illinois when my report on the Illinois stonefl\' fauna was published in 1935, I am presenting illustrations, fig. 19, to aid with its recognition. The struc- tural features of both male and female show decepta to be much more closely re- 258 Illinois Natural History Sur\uv Bulletin I'ol. 12. Art. 2 lated to tenuis (Pictet) than to claassttii Frison. New locality records are as follows. IiLivo'.s.— FlEROt). spring tributarv to Ciib- hoiis Creek: Mav 24. 1940, C. C). Mohr & B. I). Burks. 3c5 (- reared), 3 9,7 nvmphs; May 29, 1939, B. n. Burks & C T. Riesel, 26, 1 iivmph; Mav 30, 1940, B. P. Burks, 4 nymphs. Edoyvu.le, Lusk Creek: Mav 24, 1940, C. O. Mohr & B. 1). Burks, 2 c5 , 29. 5 nymphs; June 1, 1940. B. D. Burks, \6, 29, 1 nymph. Florida.—Leon Countv, 12 miles west of Tall\h.\ssee: Nov. 30, 1939, L. Berner, 2S. Ceorcax.—Rabun County, small creek How- ing into Lake Burton: June 22, 1940, H. H. Mubbs. 16- Maine.—New Limerick, Hunter Brook: Aug 25, 1937, T. H. Frison & T. H. Frison, Jr., 2c5. Minnesota. — Lake County, Encampment River: Aug. 5, 1939, B. T. Peters & R. H. Daggy, 5 6 ; July 4, 1938, H. Knutson, 16. New Brunswick. — Anacance: Aug. 21, 1939, T. H. Frison & T. H. Frison, Jr., l^- New York.—Cold Brook: June 22 and 30, 1940, H. Dietrich, 6 6, 9 9- Caroline, Wild Flower Reserve: Aug. 16, 1928, T. H. Frison, 44. North Carolina.—Newfound Gap: June 13, 1935, H. H. Ross, 26 Nova Scotia.—Moser River, Goldmine Brook cascades: July 19, 1939, J. A. C. Nicol, 86- Springhill JiJnction: Aug. 21, 1939, T. H. Frison & T. H. Frison, Jr., 36- Moose River: Aug. 21, 1939, T. H. Frison & T. H. Frison, jr., 16- Incramport: Aug. 22, 1939, T. H. Frison & T. H. Frison, Jr., 16- t)NTARio. — Algonquin Park, Costello Lake: various dates, June, Julv, August and Septem- ber, 1938 and 1939, W. M. Sprules, 6 6, 9 9. Tennessee. — CJatlinburc: June 13, 1940, T. H. Frison rt al., 5 6 ; Sept. 4, 1940, B. D. Burks, 4 6, 99. Virginia.—Mountain Lake, Hunters Branch, 3,500 feet elevation: July 28, 1941, A. C. Cole, \6, 29. Several nyinphal specimens show anal ^\\\i, as first illustrated for claasseiii ( F^rison \9i5n). Since tenuis (Pictet) nvmphs also show these anal gills, all three of the Illinois species of Leuctra possess them. These anal gills are so deli- cate, however, that they are easily lost by the nymphs or overlooked in specimens. Leuctra tenuis (Pictet) Nemonra tenuis Pictet (1841, p. 375). Orig- inal description. As in the case of decepta Claassen, the findinfi of tenuis in a segregated relic habitat in Illinois adds another species to the Illinois stonefly faunal list. Its find- ing is additional evidence that each local- ity, stream and other habitat, no matter how restricted, must be searched repeated- ]\ at \arious seasons of the year if state faunal lists of stoneflies are to approach completeness. Diagnostic structures of the adult insects of tenuis are illustrated in fig. 20. The type of tiiiuis came from Pennsylvania, and Needham & Claassen (1925) have added the additional state record of New York. The geographical range of this species will un- doubtedly be greatly expanded with future collecting, as the following new records for its occurrence indicate. Illinois.—Elgin, Botanical Gardens: Sept. 19, 1939, H. H. Ross & C. O. Mohr, 9$, 49- Maine.—New Limerick, Hunter Brook: Aug. 25, 1939, T. H. Frison & T. H. Frison, Jr.. Michigan.—Otsego County, west branch Sturgeon River: June 24, 1936, J. W. Leonard, 26,29; July 9, 1937, F. E. Lyman, 16, 19. 9 Abdominal sternites cT Abdominal tergites d" Abdominal sternites cT Abdominal segments Fig. 20. — Leuctra tenuis. September, 1942 Prison: North American Plecoptera 259 Cheboygan County, west branch Sturgeon River: July 3, 1938, J. W. Leonard, 2 <5 , 29. Montmorency County, Hunt Creek: Aug. 30- Sept. 3, 1940, J. W. Leonard, 3^, 1$. Missouri.—Greer Spring: June 7, 1937, H. H. Ross, 2c^ , 29. New Brunswick. — Peticodiac: Aug. 21, 1939, T. H. Prison k T. H. Prison, Jr., 105 . Anagance: Aug. 21, 1939, T. H. Prison & T. H. Prison, Jr., 2$, 5 9- New York.—Caroline, Wild Plower Re- serve: Aug. 16, 1928, T. H. Prison, 16. Stratford, Trammel Creek: July 19, 1934, H. K. Townes, 1$ , 2 9- Nova Scotia. — Moser River, Goldmine Brook: July 29, 1939, J. A. C. Nicol, 2$, 29- Chester Basin: Aug. 23, 1939, T. H. Prison & T. H. Prison, Jr., 4$, 79, 5 nymphs. Ingramport: Aug. 22, 1939, T. H. Prison & T. H. Prison, Jr., 19- Ontario.—Algonquin Park, Costello Lake: June and July, 1938, and June, July and August, 1939, W. M. Sprules, 6 6, 9 9. Tennessee. — Chimneys Camp Grounds, Great Smoky Mountains National Park: July 21, 1939, A. C. Cole, 16 . Several nymphs show remnants of anal gills as first recorded for claasseni (Frison 1935(7) and also as noted for nymphs of decepta Claassen in this paper. Evidently such anal gills are to be expected in many if not all nymphs of Leuctra. They are very easily overlooked because of their delicate nature and are probably usually lost in handling. Leuctra occidentalis Banks (1907) Leuctra purcellana Neave (1934) Leuctra forcipata Frison (1937) Leuctra sara Claassen {\9ilb) The study of a large series of specimens of any stonefly species is almost certain to show that slight variations of some struc- tures in most species, and more in others, are to be expected. The genus Leuctra presents a group of species with very con- spicuous morphological differences in most of the males named to date and less distinc- tive differences in the females. One of the first described and a common western species of this genus is occidentalis Banks (1907). The male of this species h one of several having the anal cerci strongly sclerotized and peculiarly shaped. A taxonomic problem arises in determining which departures in shape of this structure from the typic occidentalis should be con- sidered, at least for the time being, as spe- cies and which as simply variants. Fig. 2L:/, B and C shows the character of this structure in specimens from three different states, Oregon, Montana and California, respectively. A study of series of speci- mens indicates that the observable differ- ences in these specimens is of the variant order. Fi4. 21.- Leuctra occidentalis: A from Oregon, B from Montana, C from California. Fig. 22. — Leuctra purcellana from Prairie Hills, British Columbia. d" Cercus Fig. 23.- Leuctra forcipata from Oregon. cf Cercus d" Cerc Fig. 24. — Leuctra sara: A from Massachusetts, B from Indiana, C-F from Tennessee. 260 lii.iNois N.MiR.Ai. History Survhv Hli.i.ktin I ol. 22, Art. 2 Since oiiitifti talis was described, three additional specific names of closely related tornis have been proposed. V\g. 22 shows the modified anal cercus of a male speci- men from "Prairie Hills, B. C. July 1^. 1*>()S," in the collection of the American Kntomolo^ical Society of Philadelphia, which ajirees very well with pumllaiKt Nea\e (1'534) described from British Columbia. Fig. 23 shows the modified anal cercus as it exists in specimens from Oretjon that 1 described (1937) under the name of forcipatn. Clanssen {VMl h) proposed the name of s(ira for a species of this genus from New \Ork which very closely resembles the western (iciidcn talis and the related inrcipatn and purct'llaiia. Fig. 2AA shows the character of the variation observed in the modified anal cercus from a Massa- chusetts specimen; fig. 2AB from an Indi- ana specimen ; 24C-f from Tennessee specimens. I am strongly of the opinion that all of these eastern specimens are of the same species, and the dif+erences arc due merel\ to variations in local popula- tions. The dilierences between sara and orci- dentalis are certainly slight, and there is reason to suspect that collecting in north- ern states and southern Canada will show- that sara is specifically the same as occi- (Itntalis. I he same fate in synonymy ma>' be in store for the more divergent forms described as forcipatn and purctllana. Un- til further evidence to this cfiect is pro- duced, hcwever, it seems the safest pro- cedure to hold occidentalis, forcipatn, purcellana and sara as distinct species, recognizing that certain specimens are merely variants (no names necessary) of these more widel_\ separated units. The recognition, for the time being at least, of tliese four major tvpes as species causes me to propose another specific name for an even more divergent form. Certainly, this new form deserves specific status if sara (eastern states) is held as distinct from occidentalis (western states), be- cause it is quite different from the other related forms. Leuctra projecta new species Male.—Similar in most morphological features to occidentalis Banks (1907). Differs in the shape of the modified anal cercus as illustrated in fig. 25. Fi-MALii.—Unknown but probably very similar to the female of occidentalis. Holotvpe, male.—Rockv Mountain National Park. Wild Basin, Colo.:' June 13. 1937. I'aratype. — Orkcon. — Columbia County, Scappoose Creek: Feb. 19, 1939, S. CI. Jewett, Jr.. M. The modified anal cerci of the paratvpe, fig. 25/i, differ from those of the holotype, fig. 25.7, as shown by comparing the two Fig. 25.— LciKtra projecta. drawings. I am considering the two speci- mens, however, to be of the same species because of the features in common which are verv dilierent from those of the other described species. Lenctra piojecta will fall in the group of species for which Han- son (1941) proposed the generic name of Paraleucira and which, at least for the present, 1 am considering as of subgeneric status. NEMOURIDAE Nemoura Latreille As in the case of the genus Leuctra, only one species of Kenioura was known to occur in Illinois when my paper (1935^) on the Illinois stonefly fauna was pub- lished. Recently, a second species of this genus has been found in northeastern Illi- nois, thereby necessitating the following keys for the separation of the Illinois spe- cies of Xe/nonra. KEY TO ILLINOIS SPECIES OF NEMOURA Mai.es Ciill remnants in cervical region; forward recurved part of supra-anal process nar- row and elongate ; anal cerci small, mem- branous and without special structures, fig. 26 venosa Without gill remnants in cervical region ; supra-anal process broad, somewhat knob- like, fig. 27; anal cerci elongate, strongly scleroti/.ed and with projecting points at tip trispinosa, p. 261 September, I'UZ Frison : North American Pi.ecoptera 261 Females Gill remnants in cervical region; eighth ab- dominal sternite forming a shelflike plate that is distinctly indented in middle and that protrudes from under the backward projecting posterior margin of se\enth sternite, fig. 26 \enosa Without gill remnants in cervical legion, eighth abdominal sternite not with small lobes on posterior margin showing undei backward protruding posterior maigin of seventh sternite, hg. 27 trispinosa, p 261 Nymphal head and prosternum (JAbdominal tergites ^ Abdominal sternites Fig. 26. — Nemoura venosa. Nymphs Cjills in cervical region (Frison 1935«, tig. 264) venosa \^'ithout gills in cervical region, fig. 21.... trispinosa, p. 261 Nemoura trispinosa Claassen Nemoura trispinosa Claassen (1923, p. 289). Original description, $, , $ . This species was originally described from New York specimens and subse- quently recorded by Needham & Claassen (1925) from Quebec. The finding of this species in a small, isolated relic habitat in northern Illinois, the same locality which produced the in- teresting record for Leuctra tenuis (Pic- tet), adds a second species of Nemoura to the Illinois list. It is desirable, there- fore, to present an illustration, fig. 27, of the important characters used for identify- ing the sexes. New records for this species are as follows. Fig. 27. — Nemoura trispinosa. Illinois.—Elgin, Botanical Gardens: June 13, 1939, T. H. Frison & H. H. Ross, -^6, 10$, 13 nymphs; May 9, 1939, H. H. Ross & B. D. Burks, 17 nymphs. New York.—Essex County, Artists Brook: June 23, 1940, H. Dietrich, H. Nemoura californica Claassen Nemoura californica Claassen (1923, p. 284). Original description, i, $. Nemoura lobata Frison (1936, p. 260). Original description, i . New synonymy. When lobata was described by me in 1936, I mentioned that it was "very sug- gestive of .v. ealifornica Claassen." Since then 1 have seen additional western ma- terial and during a recent visit to the California Academy of Sciences had the 262 Illinois Natural History Slr\i.v Hullkti.n I ol. 22. Art. 2 opportunity, throuyh the courtesy of Dr. E. S. Ross, to study the holotypic male in the collection there. It is now my opinion that hbata is specifically identical with ((iliforiiiia and therefore should be reli'jiateil to s\nonyiny. Allowance must be made for slight \ariations in compli- cated genitalic structures of the character represented b\ this and other stoneHy spe- cies. The allotypic female as well as male and female paratypic specimens of cdli- furnica are in the collection of Cornell University, and material in the Illinois Natural History Survey collection has been compared with these specimens. GAPNIIDAE In my 1935rt paper on Illinois stone- flies, I presented a key for the separation of the jjjencra of Capniidae occurring in Illinois. This ke> included the genera Allocopnia and Capiiia. Under the dis- cussion of Se/no (dp Ilia iiirfjliiia Banks in the present paper. I show that my ques- tionable record of a single Illinois speci- men of Capnia {vernalis Newport?), a female (1929 and 1935rt), belongs to the genus Kemocapuia and not to Capnia. However, in 1940, specimens of Capnia (ipis (Newman) were taken in northeast- ern Illinois, and it is desirable, therefore, to present a new key to the Illinois genera of Capniidae to replace the one of 1935rt. KEY TO ILLINOIS SPECIES OF CAPNIIDAE Adults 1. Eighth abdominal tergite of male with a raised process or tubercle-like struc- ture; wings sometimes absent or ab- breviated ; anal field or lobe of hind- wing, when wing is present, large and exteniling nearly out to tip of wing . Allocapnia, p. 265 Eighth abdominal tergite of male with- out a raised process or tubercle-like structure 2 2. Wings normally developed ; radial vein near point of origin with radial sector straight; no oblique crossvein beyond end of subcosta in forewing; posterior margin of large, fiarkly sclerotized medial area (mesobasisternite) of mes- osternum but slightly produced back- ward, fig. 28 Nemocapnia, p. 262 Wings normally developed, absent or ab- breviated ; radial vein near point of origin with radial sector slightly but distinctly bent forward; usually an ob- li«|ue crtiss\'cin beyond end of sulKosta in forewing; posterior margin of large, darkly sclerotized medial area (meso- basisternite) of mesosternum strongly produced backward, Hg. 28 Capnia, p. 264 Nymphs (Nymphs homogeneous with respect to good key characters; mature nymphs freriuenlly rc\eal characters used in adult key.) Wing pads present in most species, but ab- sent or rudimentary in a few species; anal field or lobe of hindwing, when pad is present, large and extending out nearly to length of wing; mesobasisternite of meso- sternum, when boundary limits are visible, same as for adults, fig. 28 Allocapnia, p. 265 Wing pads always present; anal field or lobe of hindwing reduced and extending about to middle of wing length ; meso- basisternite of mesosternum, when bound- ary limits are visible, same as for adults, fig. 28 Nemocapnia, p. 262 \\'ing pads present, absent or rudimentary; anal field or lobe of hindwing, when pad is present, reduced and extending about to middle of wing length; mesobasisternite of mesosternum, when boundary limits are visible, same as for adults, fig. 28 Capnia, p. 264 Nemocapnia Carolina Banks Nrmocapnia Carolina Banks (1938, p. 74). Original description, i, $. Capnia sp. Prison (1929, p. 407). Errone- ous generic assignment. Capnia {vernalis Newport?) Prison (1935^, p. 356). Erroneous generic assignment. In my paper on the Fall and Winter Stone/lies, or Flecoptera, of Illinois (1929), I questionably recorded a female specimen of a capniid from Grayville, 111., March 8, 1928 (collected by T. H. Prison & H. H. Ross) as ''Capnia sp." and in commenting concerning this specimen sug- Capnia oris September, 1942 P'rison : North American Plecoptera 263 gested it might be the female of Capnia vernalis Newport. Additional material of this species was not in hand in 1935 and so in my later and more compre- hensive report of the Illinois stoneflies (1935a) I again cited this Illinois record and its questionable assignment to vernalis. On the basis of several old specimens from "Morgantown, N. Car. (Morri- son)" in the collection of the Museum of Comparative Zoology, Banks (1938) de- scribed a new genus, Neniocapnia, includ- cTAbdominal tergites 9SUBCENITAL PLATE ing in it a single species described as new under the name Carolina. After seeing the typic specimens in 1939, I realized that the female Illinois specimen questionably re- corded as Capnia vernalis in my papers of 1929 and 1935^ was N. Carolina Banks and not the female of a species of Capnia. Both males and females are easily recog- nized because of the characters of the wings. Although no seasonal data are as- sociated with the typic specimens, the date of capture of the Grayville, 111., specimen on March 8, 1928, and collection of other specimens in other states, places this spe- cies in the winter faunal list. To facilitate recognition of this species, I present figs. 28, 29 and 30, w^hich illus- trate the important structural characters of the adult males and females, as well as the nymphal mouthparts. The dorsal view of a nymph is shown in fig. 31. Fig. 29 represents a specimen from North Caro- lina ; fig. 30 represents specimens from Illinois and Indiana. The structure of the nymph confirms its placement in the Cap- niidae. In addition to assigning correctly now the Grayville, 111., March 8, 1928, female speci- men to the species Nemocapn'ia Carolina, there- by adding another genus and species to the Illinois list, I wish to add the following new records for the distribution of this recently described species. Arkansas.—Benton, Salt Creek: April IS, 1939, H. H. & J. A. Ross, 1^. Indiana.—Rogers, White River: April 17, d" Abdominal tergites d* Abdominal segments cT Abdominal segments Fig. 29. — Nemocapnia Carolina from North Carolina. Fig. 30. — Nemocapnia Carolina from Illinois and Indiana. 264 Illinois Natural History Survuy Bulletin {'ol. 22. Art. 2 Fi^. 31.—N'vmph of Semocapnia Carolina. 1940, C. (). Mohr & B. D. Burks, 1 9 ; April 16, 1936, H. H. Ross & C. O. Mohr, \$ ; April 21, 1936, T. H. Prison & C. O. Mohr, 19; April 14, 1940, C. O. Mohr & B. D. Burks, 29. Shoals, White River: April 5, 1940, C. O. Mohr & B. I). Burks, 1 9 . ViRf;iNL\. — South Hill, Roanoke River: Feb. 16, 1937, i $, 9 9- Remington, Rappa- hannock River: March 21, 1940, T. H. Prison et al., ^ i, 9 9, nymphs and exuviae. RucK- ersville: March 2i, 1940, T. H. Prison et al., \$. Lynchburg, Elk Creek: March 22, 1940, T. H. Prison ct al., %$, 69. Richmond, Robert P. Lee Bridge: 19. Capnia opis (Newman) Chloroperla opis Newman (1839, p. 89). Original description, $, 9. (Capnia vernaiu Needham & Claassen (1925, p. 256). Misidentification. Capnia opis Ricker (1938, p. 134). Proper synonymy revealed. Ricker (1938) has shown that opis is the same species as that redescribed and recorded by Needham & Claassen (1925) as vernalis Newport (1851). Reference to the specific name of opis by Needham &: Claassen (1925) and by Claassen (1928) is entirely omitted. Ricker (1938) further states that ver- ludis is not a s\ nonym of opis but a distinct species. Thus far, among the numerous specimens of Capnia that I have examined from North America, I have been unable to recognize more than one species, opis (= vernalis in the sense of Needham & Claassen), of Capnia from eastern North America. If vernalis is a distinct species, as Ricker states, I am unfamiliar with it, and it must have a much different general distributional range than opis. Experience with long series of specimens unquestion- ably of the same species has shown me that slight variations in structural char- acters are to be expected, and it is probable that specimens I consider within the limits of variation of opis are comparable to the specimens which Ricker (1938) consid- ered a separate species by the name of c? Abdominal SEGMENTS Fij«. 32. — Capnia opis. vernalis. Fig. 32 shows structural char- acters of specimens of opis taken from Illinois. Capnia opis was originally described from specimens collected in Newfoundland, and Needham & Claassen (1925) have added records, under the name of vernalis, from New September, 1942 Prison: North American Plecoptera 265 York and Michigan. Additional records for this species are as follows. Illinois.—Elgin: Botanical Gardens, March 20, 1940, B. D. Burks, 1 exuvia; Trout Springs, March 7, 1940, Mohr & Burks, 2$, 1$, 2 nymphs, 2 exuviae. Connecticut.—Danielson: March 24, 1937, H. H. Ross, 2$, 3$. Maryland.—Keyser Ridge: April 19, 1938, H. H. Ross, 4? ; Dec. 30, 1934, T. H. Prison & H. H. Ross, 12 nymphs. Michigan.—Ontonagon County, Shore of Lake Superior between Silver City and Onton- agon: May 15, 1935, J. W. Leonard, $$, 9$. Crawford County, Au Sable River: March 20, 21 and 23, 1936, J. W. Leonard, 3c?, 85. New York.—Clinton: March 25, 1903, 3$. Pompey Center: April 11, 1937, H. H. Ross, 1$. East Winfield: April 11, 1937, H. H. Ross, 1$. Deansburg: April 11, 1937, H. H. Ross, 3$. North Carolina.—Near Grandfather Moun- tain, west of Blowing Rock: March 23, 1940, T. H. Prison et ai, 3 $,29- Ohio.—Blacklick: Nov. 5, 1936, L. S. Roach, 4 nymphs. Hocking County: March 22, 1938, D. J. & J. N. Knull, 1?. Ontario.—Glen Major: April 7, 1934, P. P. Ide, IS, 1$. Pennsylvania. — Ebensburg: March 23, 1937, H. H. Ross, 1$, 6 nymphs. Riverside: March 22-28, 1937, H. H. Ross, 3$, 3$. Quebec. — Laurentides National Park, Long Lake: June 20, 1938, C. Gauthier, 1$. Tennessee.—Great Smoky Mountains Na- tional Park, Greenbrier Cove: March 15, 1938, A. C. Cole, 2?. Virginia.—Gore: March 17, 1940, T. H. Prison et al., 3 9. Standardsville: March 21, 1940, T. H. Prison et al., 1$. Sperryville: March 17, 1940. T. H. Prison ct al., 9$, 59- Elkton, Elk Run: March 21, 1940, T. H. Prison et al., 36, 29, exuviae. Skyline Drive, Big Meadows: March 18, 1941, B. D. Burks, 7 i , 29. West Virginia.—Erwin, Wolf Creek and tributary of Cheat River: $ $, 9 9- Kane- town: 2$, 19- Augusta, Little Cacapon River: 1,5,39. Evansville: $S, 99. Ma- comber, Cheat River: $$, 9 9, exuviae. Pellowsville: $ $, 9 9,1 nymph. All col- lected March 16 and 17, 1940, by T. H. Prison ct al. Wisconsin. — Spooner, Namakagon River: April 29, 1939, T. H. Prison & B. D. Burks, 16, 29. Allocapnia Claassen Since my paper on Illinois stoneflies (1935rt), another species of this genus has been found in Illinois, and the study of previously overlooked typic specimens makes necessary some nomenclatorial changes. These changes and additional notes, new descriptions and comments are included in the following discussions of various species of Allocapnia. Allocapnia vivipara (Claassen) Capnclla including September, 1942 Prison : North American Plecoptera 269 a mating pair. Romey: March 17, 1940, T. H. Prison et al., 3$, 3$. Iaeger, Horse Creek: Feb. 2, 1936, J. Addair, 1^. Maryland.—Grantsville, Shade Run: Feb. 13, 1938, R. E. Yeatter, 1^. This species is easily distinguished from all other species of Allocapnia. The males, in having a tubercle on the seventh ab- dominal tergite, suggest forbesi Frison and illi/ioensis Frison, but the shape and gen- eral arrangement of all tubercles is quite different. The females are unique be- cause of the pronounced lobelike projec- tion of the posterior margin of the seventh sternite. The seventh and eighth sternites are slightly fused beneath the lobelike pro- jection of the seventh sternite, but this at- tachment is readily broken so that a mem- branous transverse strip may seem to be present between these sternites beneath the lobe. Allocapnia virginiana new species Male.—Similar in general features to curiosa Frison. Differs from this and other species of the genus as follows. Ab- domen with first seven tergites without tubercles, a narrow, median, pale, longi- tudinal, membranous-like stripe on first four basal tergites; eighth tergite, fig. 35, with a large, odd-shaped, robust tubercle which in turn has a small, pointed tubercle on anterior face or margin ; recurved supra-anal process very short, broad and shaped as in fig. 35 ; ninth and tenth ter- gites broadly cleft for reception of supra- anal process. Female.—Similar in most morphologi- cal features to the male. Wings extending to tip of abdomen; a wide, median, dorsal, longitudinal stripe extending from base of abdomen to hind margin of eighth tergite, last two tergites entirely and darkly scle- rotized ; seventh abdominal sternite simi- lar to those preceding; eighth abdominal sternite with a darkly sclerotized subgeni- tal plate shaped as in fig. 35. Holotype, male. — Shelby, Rapidan River, Va.: Jan. 1, 1939, T. H. Frison & B. D. Burks. Allotype, female.—Same data as for holo- type. Paratypes. — Virginia.—Shelby: Same data as for holotype, 2$, 4$. Madison: Jan. 1, 1939, T. H. Frison & B. D. Burks, \$, 6$. Remington, Rappahannock River: Dec. 31, 1938, T. H. Frison & B. D. Burks, 2$, 2?. The shape of the supra-anal process and structures on the eighth abdominal tergite separate the male of this species from males of all other known species of Allo- capnia. The female of this new species cf Terminal Abdominal Segments POSTERIOR KNOB Eighth ANTERIOR KNOB Tergite Dorsal Supra-anal Process 9 subgenital Plate Ventral Supra-anal Process Fig. 35. — Allocapnia 'virglniana. belongs to the group of species having only the last two dorsal abdominal tergites darkly sclerotized and with a pale, mem- branous, transverse stripe between the sev- enth and eighth abdominal sternites; it differs, however, in shape of subgenital plate. The male and female are associ- ated on the basis of their collection to- gether at the same time at three different localities. Allocapnia rickeri new species Allocapnia pyymaca Frison (1929, p. 396). Misidentification. Allocapnia pygmaea Frison (1935rt, p. 367). Misidentification. As mentioned in the discussion under pygmaea (Burmeister), certain Illinois specimens of Allocapnia once recorded by me (1929 and 1935^) as pygmaea, and also many similar specimens in the Illi- nois Natural History Survey collection from other localities, require a new spe- cific name. I propose, therefore, for this species of Allocapnia the name of rickeri in honor of Dr. William E. Ricker, who 268 Illinois Natlral History Survey Bulletin Vol. 22. Art. 2 2. 1939, Prison & Burks, 3 i, 19. Midmount: Jan. I, 1939, Prison Sc Burks, 1 5a papers under the name of pyt/miita. It seems necessary Fig. 36. — Allocapnia rickeri. to present here, therefore, only a brief review of the most salient characters need- ed for recognition of rickeri and new illus- trations for comparison with those of the true pygmaea. Malk.—Similar in general features to curiosa Frison as described in this paper. Certain characters peculiar to rickeri and separating it from other species are aa follows: Wings short and usually extend- ing about half the length of abdomen; seventh abdominal tergite without sug- gestion of any tubercle, eighth tergite with two rather low and definitely separated tubercles, ninth and tenth tergites with middle area depressed and membranous for reception of supra-anal process; supra- anal process, fig. 36, with a short head. Fkmale.—Similar in most morphologi- cal features to the male. Wings reaching about to or slightly beyond tip of ab- domen; a wide, median, dorsal, longitudi- nal stripe extending from base of dorsum of abdomen to hind margin of eighth ter- gite, last two tergites entirely and darkly sclerotized ; seventh and eighth abdominal sternites fused in middle and without transverse membranous strip between them ; subgenital plate shaped as in fig. 36. Holotype, male. — Golconda, Big Grand Pierre River, 111.: March 7, 1928, T. H. Frison & H. H. Ross. Allotype, female.—Same data as for holo- type. Holotype and allotype represent a mating pair. Paratypes. — Illinois.—Apple River, north- west of Apple River Canyon State Park: March 2, 1938, Ross & Mohr, 112 ,J, 27$. Bloomfield: March 7, 1928, on concrete foundation of bridge, Frison & Ross, 13 3 1 2$. Dixon Springs: Feb. 2, 1934, Frison & Mohr, 54 cJ, 2 9, 1 mating pair. ElCHORN: March 6, 1928, Frison & Ross, 42 <$ , 8 $ ; Buck Creek, on bridge, Frison & Ross, 21,5, 11$. Golconda, Big Grand Pierre River, on and near bridge: March 7, 1928, Frison & Ross, 75 6, 32$, 4 mating pairs. Gorham : Feb. 3, 1934, Frison & Mohr, 1^, !$• Herod: Gib- bons Creek, under bark of tree hanging over stream, March 6, 1928, Frison & Ross, I $ ; Gibbons Creek, on stones and debris in and near margin of stream, 47 5, 30$, 1 mating pair; April 19, 1937, Ross & Mohr, 1$ ; Rose Creek, foundation of concrete bridge, March 6, 1928, Frison & Ross, 1 mating pair; Big CJrand Pierre River, foundation of concrete bridge, March 6, 1928, Frison & Ross, 1$. Herod-Elizabethtovvn, Hicks Branch Creek: March 6, 1938, Frison & Ross, Z$. Jonesboro: Feb. 3, 1934, Frison & Mohr, SO $ , 4$. New Columbia, Clifty Creek: Dec. 26, 1932, Harp- er, 4,5. Thebes: Feb. 3, 1934, Frison & Mohr, 4(j. Vienna, on concrete foundation of bridge: March 7, 1928, Frison & Ross, 1$. Warren, tributary of Apple River: March 2, 1938, Ross & Mohr, 1115, 8$. Other specimens of this species examined, but not included in paratypic series, are as follows. Illinois.—Golconda, Big Grand Pierre River: March 7, 1928, Frison & Ross, many nymphs. District of Columbia.—Washington, Po- tomac River: Feb. 5, 1938, Gurney & Burks, 15. Indiana.—Bacon: creek southwest of town, Feb. 14, 1938, Frison & Mohr, 5 5, $$, 3 mating pairs; Patoka River northwest of town, Feb. 14, 1938, Frison & Mohr, $$, $ $. English, creek north of town: Feb. 14, 1938, Frison & Mohr, 5 5, $$, 1 mating pair. McCormick Creek State Park: March 14, 1936, Frison & Ross, ^ $, $ $. Marengo, creek west of town: Feb. 14, 1938, Frison & Mohr, 5 5, 2$. Medora, creek northwest of town: Feb. 14, 1938, Frison & Mohr, 25- MiLLTOWN, creek west of town: Feb. 14, 1938, Frison & Mohr, 85, 1$. Needmore, creek near town: March 14, 1936, Frison & Ross, $$, $ $, 3 mating pairs. Palmyra, Blue River north of town: Feb. 14, 1938, Frison & Mohr, $ $, $ $. Paoli, south of town: Feb. 14, 1938, Frison & Mohr, 5 5, $$, many mating pairs. Salem, river south of town: September, 1942 Frison : North American Plecoptera 271 Feb. 14, 1938, Frison & Mohr, 6,^, 4$. Springville: Feb. 14, 1938, Frison & Mohr, $ $, $ ?. Turkey Run State Park: March 18, 1933, Frison & Mohr, 1$; Sugar Creek, April 19, 1933, Frison & Mohr, 2 5. Willow Valley: March 14, 1936, Frison & Ross, $ $, 1$. Kentucky.—Trenton: Jan. 5, 1939, Frison & Burks, $ $, 6$. Maryland. — Emmitsburg: Feb. 14, 1937, %$, 3$. Indian Springs: Feb. 2, 1936, Frison & Ross, \$, 3$. New York.—Ithaca: March 15, 1922, 2$, 2? ; Beebe Lake, March 18, 1935, 1$. North Collins: April 13, 1937, H. H. Ross, 1$. Ohio.—Little Hocking, White Run Creek: March 16, 1940, T. H. Frison et al., 3$, 1$. New Concord: Jan. 6, 1935, H. H. Ross, $ $, 3$. Pennsylvania.—Amity Hall, on Route U. S. 22: Feb. 17, 1938, R. E. Yeatter, $ S, 69- Claysville, 5 miles east on U. S. 40: Feb. 13, 1938, R. E. Yeatter, 15- Emerickville, V/j miles east of town: Feb. 18, 1938, R. E. Yeat- ter, $ S, ? ?. Grampian, Kratzer Run: Feb. 18, 1938, R. E. Yeatter, 1^. Northumber- land: March 23, 1937, H. H. Ross, $ $ , 49 . Van, East Sandy Creek: Feb. 18, 1938, R. E. Yeatter, $ $, 9 $ . Tennessee.—Bristol: Jan. 2, 1939, Frison & Burks, 1$. Goodlettsville: Jan. 5, 1939, Frison & Burks, IS, 1$. Johnson City: Jan. 2, 1939, Frison & Burks, $ 6,4$. McDonald : Jan. 4, 1939, Frison & Burks, 6 6,15,2 mat- ing pairs. Springfield, Sulphur Fork Creek: Jan. 5, 1939, Frison & Burks, $ $, $ 5. Virginia.—Afton: March 22, 1940, Frison, Mohr & Hawkins, 6 6,25. Bull Run, Bull Run Creek: March 21, 1940, Frison, Mohr & Hawkins, 16- Cedarville: March 17, 1940, T. H. Frison et al., 3 6 • Culpeper, Gaines Run Creek: March 21, 1940, Frison, Mohr & Hawkins, 16, 15- Elkton, Elk Run: March 21, 1940, Frison, Mohr & Hawkins, 6 6, 3 5. Elliston, Roanoke River: Jan. 2, 1939, Frison & Burks, 16, 15- Fairfax: Jan. 2, 1935, T. H. Frison, 2 6 ; Dec. 31, 1938, Frison & Burks, 3 mating pairs; March 21, 1940, Frison, Mohr & Hawkins, 16. Fair- field: Jan. 1, 1939, Frison & Burks, $$, 5 5. Fort Chisvvell: Jan. 2, 1939, Frison &c Burks, 16, 15. Gore: March 17, 1940, T. H. Frison et a!., 9$, 45, 3 mating pairs. Greenville, Christian Creek: Jan. 1, 1939, Frison & Burks, 6 6,1 mating pair. Grot- toes, Mill Creek: Jan. 1, 1939, Frison & Burks, Si, 5 5,6 mating pairs. Hunter: Jan. 30, 1938, Gurney & Burks, 96, 25. Marion, Hoi- ston River: Jan. 2, 1939, Frison & Burks, 15. Port Republic: North River, Jan. 1, 1939, Frison & Burks, 26, 15; March 21, 1940, Frison, Mohr & Hawkins, $ S, 1 5,1 mating pair. Radford: Plum Creek, Jan. 2, 1939, Frison &c Burks, SS, 65, 1 mating pair; March 22, 1940, Frison, Mohr & Hawkins, 3 5. Riverton: March 17, 1940, T. H. Frison et al., 26, 1$. Roanoke, Mud Lick Creek: Jan. 2, 1939, Frison & Burks, 25- Shawsville: Jan. 2, 1939, Frison & Burks, 36- Vienna, Indian Run Creek: Feb. 13, 1938, B. D. Burks, $ $, 65. Warrenton: March 21, 1940, Frison, Mohr & Hawkins, 3 6, 25. Winchester, Hogue Creek: March 17, 1940, T. H. Frison ct al., 46, 15, 1 mating pair. West Virginia. — Evansville: March 16, 1940, T. H. Frison et al., 46, 45. Prunty- town: March 16, 1940, T. H. Frison et al., 16. Shaffenaker: March 17, 1940, T. H. Frison et al., \$. Smithburg: March 16, 1940, T. H. Frison et al., 2$. Volcano: March 16, 1940, T. H. Frison et al., 6 6, 5 5- PERLIDAE Perlesta placida (Hagen) Perla placida Hagen (1861, p. 28). Orig- inal description, 6, 5. Perlesta placida is one of the most vvidel}^ distributed species of stoneflies in North America, and large series of speci- mens from various localities reveal con- siderable variation. It is not my inten- tion to go into detail in this paper con- Fig. 37.—Nymph of Perlesta placida. 272 Illinois Natlral Hisiory Slrvkv Bulletin To/. 22. Art. 2 cerning the ramificitions of this variation. However, it seems desirable to illustrate a form which is commonly encountered in the Great Smoky Mountains National Park near Gatlinburg, Tenn., because its identity mi^ht be overlooked. The nymph of this variant is shown in iig. 37. Fiy. 38.y is a dorsal view of the head and pronotum of this variant, and fig. 38/i Adult head and pronotum Fiji. 38. — Perlesta placida: A from Great Smoky Mountains National Park, B from lower altitudes. is the same view of more nearly typical specimens taken at lower elevations. The difterence in color pattern is quite notice- able even in old pinned specimens. The nymph of this variant, fig. 37, differs from t\pical specimens from elsewhere in its generally lighter color and in the com- parative absence of numerous short, stout setae which usually give the nymphs a freckled appearance (Frison 1935a, figs. 307 and 308). Acroneuria arida (Hagen) Perla arida Hagen (1861, p. 18). Original description, i , $ . Pcrla valiJa Banks (1906rt, p. 32). Orig- inal description, $. Previously correctly syn- onymized by Needham & Claassen (1922). Acroneuria arida Needham & Claassen (1925, p. 185). In part. Acroneuria arida Claassen (1940, p. 172). Catalogue—in part. Through the courtesy of Dr. Nathan Banks, I have had the privilege of study- ing in considerable detail the types of Perla arida Hagen ( 1 female, No. 14,386) and P. valida Banks (1 female, No. 11, 315), both in the collection of the Mu- seum of Comparative Zoolog}'. Because of the importance of establishing the pres- ence or absence of anal gill remnants on the subanal lobes, the apical abdominal segments of the typic female of arida from "Philadelphia—VVinthem" were clipped from the abdomen, softened in potassium hydroxide and studied in fluid. The typic female of valida is from "Wavnesville, N. C, July, 1901, F. Sherman, Jr." Needham & Claassen (1922) were cor- rect in placing valida as a synonym of arida, but in 1925 they confused another species with arida which led me (1935a) to an erroneous assignment of certain Illi- nois specimens to this species. These Illi- nois specimens belong to a species which was described later by Claassen (1937/>»), on the basis of a single adult female, as prolonga, which in turn is a synonym of evoluta Klapalek, as I am now using this name. Studies of the types involved, the rear- ing of evoluta (= arida Frison 1935fl) and comparisons of extensive material in the Illinois Natural History Survey col- lection all have established that evoluta is a species with anal abdominal gills in the nymph and subanal gill remnants in the adult, and that arida (= valida) lacks such structures in the adult, and, of course, this means that the nymph when discov- ered will not possess anal abdominal gills. A fundamental character for the sepa- ration of arida from evoluta, as now recog- nized, having been established, the differ- ences previously observed in the shape of the subgenital plate of the females become understandable as specific differences. In arida, the subgenital plate is much con- stricted at its base, fig. 39, so that the end portion is much broader than its base, whereas in evoluta the base is not, or but slightlv, constricted (Frison 1935fl, figs. 242-3). Although Klapalek (1909) records three males and one female of valida from "North Carol. Morr." in the Selys Long- champs collection, no description or illus- tration is given of the male, and it is possible that these specimens, particularly the males, are not arida. Klapalek failed to recognize arida as a valid species and erroneously placed it in the synonymy of arenosa (Pictet). Since the male of arida has not been previously described (Needham & Claas- sen 1925 description is undoubtedly male of evoluta), I present fig. 39 and the fol- lowing brief description. Male.—General habitus the same as for other species of A croneuria from North America. Dorsum of head yellow September, 1942 Prison : North American Plecoptera 273 with pattern of dark brown markings as in fig. 39. Pronotum with raised rugosi- ties and a narrow, yellow, longitudinal median line. Terminal abdominal tergites with groups of small spinulae arranged as 9SUBGENITAL PLATE (JABDOMINAL STERNITES Fig. 39. — Acroneuria arida. in fig. 39. Genital hooks or modified sub- anal lobes of the finger-like type with a distinct notch on inner margin at tip. Ninth sternite with a small, nearly round, padlike disk. Subanal lobes show no trace of gill remnants. Allotype, male.—Knoxville, Tenn. : June 21, 1939, A. C. Cole. The subgenital plate of the female of arida was figured by Banks at the time of the original description of valida, but to aid recognition of this species another illustration of this structure, fig. 39, is presented. The nymph of this species has not as yet been discovered. In addition to the records from North Caro- lina and Philadelphia (Pennsylvania) given in the original descriptions, I can now add the following. Georgia.—Summerville: June 9, 1937, P. W. Fattig, S$, 7$. Ringgold, Chickamauga Creek: June 14, 1939, P. W. Fattig, 56, 6$. Ball Ground: June 27, 1932, P. W. Fattig, 1$. Ellaville, Cedar Creek, 10.7 miles north: May 26, 1939, P. W. Fattig, 2 $ . Tennessee.—Knoxville: April 24, 1936, C. B. Huffaker, 1? ; May 26, 1936, C. B. Huf- faker, 1^ ; June 1, 1936, D. A. Johnson, 1^ ; June 6, 1936, D. A. Johnson, 1^ ; May 22, 1939, A. C. Cole, 2? ; June 14, 1939, A. C. Cole, 1$ ; June 21, 1939, A. C. Cole, 2$, 4$. Sevierville: June 11, 1938, at light, T. H. Frison & T. H. Frison, Jr., 1$. Greenbrier Cove, Smoky Mountains: June-July, 1940, A. C. Cole, \$, 19. Monteagle: A. C. Richards, 2$. Acroneuria evoluta Klapalek Acroneuria evoluta Klapalek (1909, p. 245). Original description, $. Larva No. 1—Garman (1912, p. 59, fig. 47). Nymphal description. Acroneuria arida Needham & Claassen (1925, p. 185). In part. Acroneuria evoluta Clark (1934, p. 121). Acroneuria arida Frison (1935a, p. 395). Misidentification. Acroneuria prolonga Claassen (1937/-', p. 42). New synonymy. Acroneuria evoluta Ricker (1938, p. 138). Notes on type. Acroneuria arida Claassen (1940, p. 172). Catalogue—in part. In my remarks concerning the synonymy of arida (Hagen), I have called attention to the fact that Needham & Claassen (1925) confused two species under the name of arida. One of these species, arida (Hagen) = valida (Banks), lacks gill remnants on the subanal lobes of the adults and hence has nymphs lacking anal abdominal gills. The second of these spe- cies has anal abdominal gills in the nymphs and shows gill remnants on the subanal lobes of the adults {evoluta = arida as used in the sense of Frison 1935«). Due to the confusion of species in liter- ature at the time of publication of my 1935^ paper, the Illinois records of arida reported by me at that time apply to the species here called evoluta. It is obvious from this situation that my placement then of evoluta as a synonym of arida does not hold, and evoluta becomes available as the name for this Illinois (1935fl) material. Ricker's (1938) notes on the type of evoluta are the basis for my use now of the name evoluta for the Illinois material recorded (1935^) as arida. Ricker states that his study of evoluta "indicates that it is synonymous with arida Hagen, as earlier suggested by Frison." It should be pointed out that at the time of Ricker's article the arida in the sense of Frison is not equiva- lent to the true arida (Hagen) but to a species for which the first name available now appears to be evoluta. In 1937, I adopted the use of the name 274 Ii.i.iN'ois Natural History Survey Bulletin J'ol. 21. Art. 2 ex'oluta for an Illinois species heretofore confused \vith arida as used in the sense of Frison I'^^Srt. Tlie transfer now of the name evoluta to my arida material of 1935rt leaves the species called evoluta in 1Q37 "without a name," as Ricker (1938) has earlier suggested. Part of the material listed by Needham & Claassen (1925) as arida belongs to the species 1 am now recognizing as arida {^= valida) and part belongs to the spe- cies I am here recognizing as evoluta. Clark's (1934) record of evoluta from Put-iii-Bay, Ohio, mentioned as belonging to arida in my 1935^ paper, again becomes part of the bibliography of evoluta as here recognized. Since Carman's (1912) de- scription of "Larva No. 1" and his fig. 47 are equivalent to arida in the sense of Frison 1935^, it also must be included in the bibliography of evoluta as now ac- cepted. Acroiieuria prolonya Claassen (1937^*) was described on the basis of a single fe- male from "Bridger Mountains, Montana, June 19, 1914." I have studied this type in the collection of Cornell University and consider it to be the same as my arida material of 1935<'/, which I am now calling evoluta as a result of Ricker's remarks concerning the type. Any differences which might be observed between the sub- genital plates of evoluta, as now accepted, and prolouga are certainly slight and I believe well within the range of individual variation. For the convenience of other students and the bibliographic record, I have given the complete bibliography of evoluta to date. My only question is whether the name of evoluta is even now being cor- rectly used, a matter impossible to investi- gate further at this time. Acroneuria mela new species Acroneuria evoluta Needham k Claassen (1925, p. 186). At least in part. Acronniria arida Claassen (1931, p. 81, figs. 202 and 207). Nymph. Acroneuria sp. a Frison (1935rt, p. 405). Nymphal description. Acroneuria evoluta Frison (1937, p. 79). Additional descriptive material and associa- tion of nymph. Acroneuria evoluta Claassen (1940, p. 173). C.atalocjue. As already mentioned in connection with evoluta Klapalek, it is necessary at this time to give a new specific name to the species illustrated and mentioned by me (1937) under the name of evoluta. In my article of 1937, I mentioned the possi- bility that my use of the name of evoluta for certain Illinois material, following its use "by Needham & Claassen (1925) for Fig. 40.— Acroneuria mela. " Adult head and pronotum similar specimens from Kansas," was some- what dubious. Ricker (1938) has made a recent study of the typic female of evoluta in the collection of the Vienna Museum, and he states that it is not the same as the evoluta of Frison 1937 but "synonymous with arida Hagen [sense of Frison], as earlier suggested by Frison (1935:95)." When Ricker made his study of the type of evoluta he had available the published illustrations and descriptions (Frison 1935, 1937) to separate the two Illinois species at one time lumped as arida, but was not aware that the true arida (Hagen) = valida (Banks) was yet an- other species. This explains his statement of "synonymous with arida Hagen." Claassen's (1931) reference in his key to the nymph of arida, and his drawing (fig. 202) and photograph (fig. 227) of this njmph, should now be assigned to the bibliography of this new species since they are the same as my species a of 1935/-/ and evoluta of 1937. Since this species has been confused in literature, and since, except for notes and illustrations in my stoneHy paper of 1937, no single description certainly applies al- together to this species, I consider it ad- visable to treat it as a new species rather than to propose a new name as an append- age to previously mixed literature. Male.—General habitus the same as for other species of A croueuria from North America. Dorsum of head yellow with a pattern of dark brown markings as in fig. 40. Pronotum with raised rugosi- September, 1942 Prison : North American Plecoptera 275 ties and a long;itudinal, median depressed line. Terminal abdominal tergites with groups or patches of small spinulae ar- ranged as in fig. 64 of Frison 1937. Gen- ital hooks or modified subanal lobes taper- ing to a point which is curved inwards at tip (fig. 64, Frison 1937). Subanal lobes show gill remnants. Female.—Head, thorax, basal abdom- inal segments and appendages in general similar to those of male, but slightly larger in size. Important differences are as fol- lows : eighth abdominal sternite modified into a subgenital plate extending partly over ninth sternite and shaped as in fig. 64 of Frison 1937. Holotype, female.—Petersburg, Ind. : reared from nymph from White River, June 11, 1936, T. H. Frison & C. O. Mohr. Allotype, male.—Same data as for holotype except reared June 9, 1936. Paratypes.— Indiana.—Petersburg: Same data as for holotype and allotype with rearing dates as follows: June 3, 1 $ ; June 4, 3 $ ; June 8, 1mphs of Acroneuria (Prison 19.S5r/). Body and appendages mostly uniformly yellowish brown, with- out a prominent, contrasting, dusky or dark color pattern, except on dorsum of head, fig. 46. Head with a distinct trans- verse occipital ridge on posterior margin between compound eyes. Maxilla, labium and mandibles as in fig. 47. Anal gills present at apex of abdomen. Approxi- mately full grown nymph with length of 1 5 mm. Needham c^ Claassen (1925) have figured the most important characters of the male and female. It should be added to their description that in fresh material the adult males are ver\ pale colored and the dark brown or dusky markings on the dorsum of the head form a ver\- distinctive pattern, fig. 47. Records for this species in the collection of the Illinois Natural History Survey are as follows. North Carolina. — Sviokemont: June 14, 1935, H. H. Ross, 1 nymph. Rainbow Gap: April 24, 1938, H. H. Ross & B. D. Burks, 1 nymph. Montreat, Lookout Cove: July 2, 1928, O. Park, 6 i . tlraybeard Mountain near MoNTREAT, west fork of Plat Creek Cove: July 7, 1928, O. Park, 16 . Tennessee.— CJatlinburc;: June 17 and 26, 1940, T. H. Prison ct al., 23, reared; Fight- ing Creek Gap, May 15, 1939, T. H. Prison Fi^. 46.—Nymph of .Icroiicuria georgiana. & H. H. Ross, 2 nymphs; Fighting Creek Gap, May 27, 1934, T.H. Prison, 6 nymphs; Little Pigeon River near Alum Cave Trail, June 17, 1938, T. H. Prison & T. H. Prison, Jr., 1 nymph; Le Conte Creek, June 18, 1938, 5 September, 1942 Prison: North American Plecoptera 281 exuviae, and June 16, 1938, 1 nymph, T. H. Prison & T. H. Prison, Jr.; Little Pigeon River, June 17, 1938, T. H. Prison & T. H. Fig. 47 Acronciiria georgiana Adult head and pronotum Prison, Jr., 1 nymph. Maryville: May, 1923, 4 nymphs. Ei.kmont, Little River: June 17, 1938, T. H. Prison k T. H. Prison, Jr., 1 nymph, 3 exuviae. Great Smoky Mountains National Park, Chimneys Camp Grounds: July 3-9, 1939, A. C. Cole, \$ . Acroneuria carolinensis (Banks) Perla carolinensis Banks (1905, p. 215). Original description, 6 , $ . Acroneuria lycorias Claassen (1931, p. 87). Nymph—new synonymy. Acroneuria lycorias Prison (1937, p. 97). Erroneous synonymy of cuestae Ricker. This is another species of Acroneuria which has been infrequently recorded in literature and confused with other species. Reared specimens of both carolinensis and lycorias (Newman) prove that Claassen (1931) erroneously associated the nymph of carolinensis with the species lycorias and failed to recognize the nymph of lycorias (= perbranchiata Neave). Illinois Natural History Survey rear- ings and collections in various states where both carolinensis and lycorias occur have led to the discovery that the nymphs of the former have no anal abdominal gills, whereas such gills are present in lycorias. A corollary of this, of course, is that the subanal lobes of the adults in both se.xes in lycorias possess anal gill remnants, whereas these remnants are lacking in carolinensis. Such an easily observed char- acter as the presence or absence of anal gills or gill remnants is most important and useful when dealing with two species which look so much alike. In 1937, I placed cuestae Ricker (1935/') in the synonymy of lycorias. This placement was in error and resulted Fig. 48.— Acroneuria carolinensis. from the erroneous identification of reared male and female specimens from New York, sent to me by Dr. P. W. Claassen as lycorias, and their association with exuviae which Dr. Claassen figured (1931) as lycorias. These adults, how- ever, are without question carolinensis and are properly associated with exuviae with- out anal gill remnants. Correctness of this association of nymphs with adults is con- firmed by rearing of an adult male of 282 Ii.i.iNois Natlrai. History Surviy Hum.etin I'ol. 22. Art. 2 Carolinensis from a n\ inph at Gatlinburg. Tenn.. and the collection of a series of nymphs and adults from the Smoky Fiji. ^^-—Nymph of Atroueuria carolinensis. Mountains region, the adults of which agree perfectly with the types in the Mu- seum of Comparative Zoology. Because of a lack in the past of definite tangible characters for the separation of lycorias and carolinensis, the latter has ap- peared in literature as a species with a very restricted distribution. It is very probable that some of the adult records given by Xeedham & Claassen for lycorias apply to carolinensis, since Illinois Natural History Survey material shows carolin- ensis to be present in several of the states of the Appalachian region. Since the head pattern of Acroneuria adults, within cer- tain limits, has some value when making determinations, an illustration of it is given. Hg. 48, to compare with similar illustrations which I have given for other species of the same genus. NvMFH.—Although Claassen (1931) has given a photographic illustration of the nymph of carolinensis, under the name of lycorias, I think it highly desirable to in- clude here the reproduction of a drawing of the nymph. A brief description of the n\mph is as follows: General color of body and appendages yellow with brown or dark markings as in fig. 49 ; particular- ly important features of the color pattern are the arrangement of the light and dark areas on the dorsum of the head and the banding of the abdominal tergites ; in color pattern the nymph is very similar to lycorias, but it differs from the nymph of lycorias in the lack of anal abdominal gills. No occipital transverse ridge on the pos- terior part of the head. Maxilla, labium and mandibles as in fig. 48. The typic series of carolinensis consists of two females and one male. No. 1 1 ,320, from the "Black Mts. VI N.C." in the collection of the Museum of Comparative Zoology. Specimens in the Illinois Natu- ral History Survey collection have been compared with these types. Through the kindness of Dr. Nathan Banks, I was per- mitted to clip off the apical abdominal seg- ments of one of the typic females, relax it and study it in fluid, a procedure which enabled me to establish that these typic pinned specimens did not possess anal gill remnants on the subanal lobes. It should be mentioned, at this time, that I believe Perla lurida Hagen (1861) is the same species as carolinensis, but hesi- tate to place carolinensis definitely as a synonym of lurida, which would have pri- ority, until more information is available about the Acroneuria fauna of Georgia, Alabama and Louisiana. The type of lurida is a female. No. 246, in the collec- tion of the Museum of Comparative Zo- ology, and bears the data "N. Orleans Pfeififer 1858," which agree with state- ments in the original description. The apical abdominal segments of this type, by permission of Dr. Banks, were clipped ofif. softened in potassium hydroxide, and studied in fluid. The subgenital plate seems to be almost identical with that of carolinensis, and the lack of any anal gill remnants on the subanal lobes is a further September, 1942 Prison: North American Plecoptera 283 very convincing bit of evidence that the two are identical. Since the distributional pattern of carulin- ensis is so poorly known, the following records, based upon the Illinois Natural History Survey collection and an examination of material sent for study, are presented. Maryland.—Keyser Ridge: Dec. 30, 193+, Prison &: Ross, 2 nymphs. New Hampshire.—North Woodstock, Bog Brook: June 21, 1941, Prison & Ross, 1 nymph. New York.—Llovd Cornell Wild Plower Preserve, Caroline': Aug. 16, 1928, T. H. Prison, 1 nymph. Ithaca: Sept 4, 1936, Harvey Bowman, 39 nymphs; Coy Glen, under stones and in grav^el of rapid waters, Oct. 6, 198 [1908?], nymphs. Downsville: Campbell Brook, Sept. 4, 1935, nymphs; June 16, 1940, H. Dietrich, 1^. McLean: May 29, 1927, \$, 1 exuvia. Wild Life Preserve, Sister- ville: June 9, 1927, 19,1 exuvia. Schoharie: June 6, 1937, Flick, 1 $ ; May 14, 1938, P. Jen- nings, 1 nymph. Keene, small creek 3 miles west, Adirondack State Park: June 20, 1941, Prison k Ross, 1 exuvia. Euba Mills, Adi- rondack State Park: June 20, 1941, Prison & Ross, 1 exuvia. Roscoe, Beaver Kill Creek: June 28, 1940, P. Jennings, 1 $ . Mount Trem- PER, Esopus Creeic: July 31, 1938, P. Jennings, 19. Beaver Kill, Beaver Kill River: July 24, 1940, R. B. Pischer, 1 nymph. Upper Beaver Kill: June 21, 1936, Nottingham, 1 nymph. Catskill: June 20, 1936, J. B. N., 4 nymphs. North Carolina.—Black Mountain, fork north of Swannanoa: May, 1^ ; VI, 2$. Pennsylvania.—Poyntelle: June 17, 1904, M. Hebard, $. Monroe County: Marshall's Creek, May 24, 1935, W. J. Harmer, 3 nymphs; Saw Creek, May 19, 1935, W. J. Harmer, 3 nymphs. Pike County, Saw Creek: May 19, 193 5, W. J. Harmer, 6 nymphs. Tennessee.—Gatlinburg: Le Conte Creek, May 14, 1939, Prison & Ross, 1 exuvia; May 14, '1939, Prison & Ross, 1^ (reared); June 13, 1940, Prison et al., many exuviae; June 14, 1940, Prison et al, 1$, 35$, 1 exuvia; June 14, 1940, T. H. Prison, 1 adult. Knox- ville: June 13, 1940, Prison et al., many exuviae; June 14, 1940, Prison ct al., 1 exuvia. Virginia—Standardsville: Sept. 27, 1936, Prison, 1 nymph. Acroneuria lycorias (Newman) Perla lycorias Newman (1839, p. 35). Orig- inal description. Acroneuria lycorias Ricker (1938, p. 139). Designates lectotypic 5. Acroneuria perbranchiata Neave (1933, p. 237). New synonymy. Newman in his original description does not give the sex of his typic specimens, but Ricker (1938) designates a female speci- men in the Hope Collection, University Museum, Oxford, as the lectotype and states that it agrees with Needham & Claassen's (1925) description of this spe- cies. Elsewhere in this article I have pointed out that there has been some mix- ing of species under the name of lycorias and that the nymph described as this spe- cies by Claassen (1931) is the nymph of carrjline)isis (Banks). A study of paratypic male and female specimens of Acroneuria perbranchiata Neave sent to the Illinois Natural History Survey collection by Neave has revealed that this species is a synonym of lycorias. I suspect that Claassen's (1931) erroneous assignment of the nymph of caroli/ie/isis Fig. 50.—Nymph of Acroneuria lycorias. to lycorias had some influence in leading to the description of perbranchiata since Neave describes the nymph of perbranchi- ata and mentions its great similarity with lycorias as described by Claassen except for the presence in perbranchiata of anal abdominal gills. 284 Ii.i.iNois Natlrai. History Survhy Hli.i.ktin I'ol. 22. Art. 2 Neave's (1933) description of the nvmph of perhranchiata is a very j^ood one and since it is identical with lycorias there is little need here for many further re- marks. Nea\e did not figure the inmph, 9 SUBGENITAL PLATE Fiji. 51. _ .i< ronntria lycorias. however, and since Claassen's figure is in error as to species 1 helieve it well to in- clude here an illustration of the nymph. The most important features of this nymph are the color pattern, fig. 50, and the presence of the anal abdominal gills. 1 he maxilla, labium and mandibles are as in fig. 51. Since the adults of lycorias have been confused with those of other species, 1 am presenting here illustrations of the color pattern of the dorsum of head and pro- notum, fig. 51, the subgenital plate of the female, fig. 51, and the dorsal apical segments of the male, all based upon reared material. Klapalek's (190Q) figure of the subgenital plate of the female of lyinrias does not agree with my figure, but Ricker has fixed a lectotype for lycorias which is similar to the illustration of Needham & Claassen (1925) and this is C(;mparable to m\ material. Very likely Klapalek's material, at least in part, repre- sents some other species. Ill addition to reared male and female speci- mens obtained on Illinois Natural History Survey field trips to Michigan, Tennessee and Wisconsin, 1 have studied reared material from Minnesota sent to me for identification. .'\ large series of adults and nymphs of this species in the Survey collection are from Florida, Maine, Manitoba, Maryland, Massa- chusetts, Michigan, Minnesota, New York, Ohio, Ontario, Pennsylvania, Tennessee and Wisconsin. Acroneuria theodora Needham & Claassen Acronrnria theodora Needham & Claassen (1922, p. 254). Original description, $, 9- Acroneuria theodora Claassen (1931, p. 90). Nymph. This species has not been recorded in literature since its description, and because of its rarity the following notes, illustra- tions and records are presented. The original description of the adults did not contain any illustrations of the structural features most important from the standpoint of identification. A few >ears later Needham & Claassen (1925) published line drawings of the apical seg- ments of the male and the subgenital plate of the female. Since these drawings are not very detailed, 1 think it worthwhile to present new drawings of these struc- tures and alio some additional ones, fig. 52, which should aid with the future recognition of this western species. Comparisons of Illinois Natural His- tory Survey material of theodora with that of californica (Banks) have revealed that the aedeagus of theodora is very dis- tinctive and differs markedly from that of californica and other species of Acro- neuria studied. Like californica, theodora belongs with the series of Acroneuria which do not possess anal abdominal gills in the nymphs or gill remnants on the subanal lobes of the adults. A. depressa Needham & Claassen (1922) and pacifica Septt 1942 Prison: North American Plecoptera 285 Banks have these anal gills in the nymphs or anal gill remnants in tlie adults. Needham & Claassen in the original description state that the males of theo- dora are "brachyterous," but give measure- ments of "length to tip of wings" for the males as "29-32 mm.," and "expanse 48- 50 mm." In their Monograph of a few years later, 1925, the "length to tip of wings" of the male is given as "15 mm.," and the "expanse—20 mm." Evidently the males vary from short-winged to long- winged forms. Two male specimens in the Illinois Natural History Survey collec- tion from Wyoming have actual wing lengths of 15 and 20 mm., and male speci- mens from Oregon have wings as long as 28 mm. Wing lengths are poor criteria for separation of species in Plecoptera. \^^^^u\i\\h'^^^\'Wu^>. >% AbdoMINAL STERNITCS Fig. 52. — Acroneuria tlieodora. Illinois Natural History Survey collection records for tlieodora are as follows. California.—Modoc County: July 20, 1922, 16. Oregon.—McKenzie River: south fork, 20 miles south from confluence, Sept. 4, 1932, R. Dimick, 16 ; Sept. 21, 1934, R. Dimick, 9$, 8$, 3 6 exuviae, 8? exuviae. Camp Creek, Mount Hood National Forest: Aug. 2, 1933, R. Dimick, 1$ nymph. McKenzie Bridge: Sept. 21, 1934, R. Dimick, 5 6 , 5 $ , 3 $ exuviae. East Fork River, Willamette National For- est: Sept. 6, 1936, V. E. Storr, 16- Boyer, foot-log on Salmon River: Sept. 22, 1935, J. A. Macnab, 16- McMinnville: Sept. 16, 1933, J. A. Macnab, 16- Summit Prairie, July 23, 1939, 16. Wyoming.—Shell Exit, Big Horn Moun- tains: July 30, 1940, T. H. F. & T. H. F., Jr., 1 6 . Bondi Camp, Big Horn National Forest, Tongue River: July 28, 1940, T. H. F. & T. H. F., Jr., 16. Acroneuria sabulosa (Banks) Pcrla sabulosa Banks (1900, p. 242). Orig- inal description, $. Acroneuria depressa Needham & Claassen (1922, p. 253). Original description, 6, 9- New synonymy. Pcrla sabulosa Needham k Claassen 1925, p. 101). New synonymy. By permission of Dr. Nathan Banks, I have had the privilege of studying criti- cally the typic female, No. 11,317, of sabulosa and the holotype and allotype, No. 15,520, of depressa in the collection of the Museum of Comparative Zoology. In order to study the typic female of sabulosa and a paratypic female of de- pressa in fluid, I relaxed the specimens and slightly softened the apical abdomi- nal segments with potassium hydroxide. Both were found to be a species of Acro- neuria which reveal traces or remnants of gills on the subanal lobes and hence must have nymphs with anal gills. No tangible differences were found to exist between the specimens ; therefore, and because of priority of description, the specific name of depressa must fall into the synonymy of sabulosa. It is interesting to note that the typic specimen of sabulosa came from "Yakima, Wash.," and the typic series of depressa came from "Yakima River, Lone Tree, June 30, '82, W. T. [= Wash.]." Under Claassenia arctica (Klapalek) in this article I have pointed out that Claas- sen (1931) erroneously described and il- lustrated the nymph of arctica under the name of Acroneuria depressa. The nymph 286 Illinois Nati r\l History Sir\i^ Hilletix J'ol. 22, Art. 2 of sabiilosa (= depressa) still remains to he discovered, but when found will possess anal abdominal jiills. Claassenia arctica (Klapalek) Aiielunyia arctica Klapalek (1916, pp. 59, 78). Original description, S, 9- I'rria lantjuida Needham & Claassen (1925, p. 100). New synonymy. Claassenia larii/iiiJa Ricker (1938, p. 140). Notes on type and generic transfer. Acronniria deprissa (?) Claassen (1931, p. 86 and pi. 27, fig. 207). Misidentification of nymph. This larjje western species of stonefly has had an interesting bibliographic his- tor\ . considering the few times it has been mentioned in literature. It was originally described by Klapalek in his new genus .! dcliinyia, with caudata from China as its genotype. In 1925, Needham & Claassen in their Monograph described languida from specimens from Wyoming and IVIon- tana, but strangely made no mention of a species arctica from "Arctic America." W'u (1934) noted that Adelungia was a preoccupied name and proposed Claassenia as the name to replace Adelungia, without any reference to its occurrence in North America. Ricker (1938) noted the close relationship between arctica and languida and placed both for the first time in the genus Claassenia. Kicker's figures of the typic specimens in the British Museum and studies of specimens in the Illinois Natural History Survey collection con- vinced me that languida is a synonj'm of arctica. Many species occurring in the mountains of northwestern states range far into Canada. Whether the species now included in Claassenia form a sufficiently distinct group to warrant generic status may be questioned, but at least for the present 1 am so recognizing them. In August, 1940, while in Yellowstone National Park. Wyo., I had an e.xcellent opportunity to rear series of arctica, both male and female, from nymphs and ob- serve some of the habits of the adults. 'I he adults are nocturnal and emerge at nightfall from nymphs which crawl out of the water on rocks or other objects near the shoreline of such turbulent mountain streams as the Yellowstone River. During the day the adults rest under stones and other objects close to the water's edge and when active at dusk or night have the abilitN to advance rapidly over the surface of the water somewhat like water-striders. Mating often takes place as soon as the females emerge from n_\mphal skins, and the males are able to recognize nymphs destined to be females as proved by at- tempts at mating and by waiting for a particular female to emerge. Claassen (1931) described and figured the nymph of arctica under the name of " Acroneuria depressa ( ?)." Certain char- acters of this nymph, particularly size, occipital ridge and anal gills, in addition to locality records, caused me to suspect its true identit\ before actuallv rearing it in 1940. Since records of the occurrence of this spe- cies are few, and confined to the references Fig. 53.—Nymph of Claassenia arctica. September, 1942 Prison: North American Plecoptera 287 Nymphal maxilla Fig. 54. — Claassenia arctica. listed above, I present the following additional data from the Illinois Natural History Survey collection. Montana.—Varney, Madison River: July 29, 1937, P. Jennings, 1 nymph. Glacier Na- tional Park, Logging Creek: July 11, 1940, H. H. & J. A. Ross, 2 nymphs, 1 exuvia. South Dakota.—Spearfish: July 25, 1924, \i ; July 27, 1940, T. H. Prison & T. H. Prison, Jr., 3 exuviae. Washington.—Seattle: C. V. Piper (col- lection of N. Banks), \$ ; Cedar River, April 1, 1939, L. Lambuth, 2 nymphs. Wyoming. — Yellowstone National Park, Oardiner River, Yellowstone River, Cascade Creek and Nez Perce Creek: July 30-Aug. 3, 1940, T. H. Prison & T. H. Prison, Jr., many nymphs, $ $ , $ $ . Grand Teton National Park, Taggart Creek: Aug. 7, 1940, T. H. Prison & T. H. Prison, Jr., 3 nymphs, 1 exuvia. Daniel, Green River: Aug. 13, 1940, T. H. Prison & T. H. Prison, Jr., 1 exuvia. Moose, Snake River: Aug. 6, 1940, T. H. Prison & T. H. Prison, Jr., 6 nymphs, 6 exuviae. Colorado.—Ida: June 19, 1934, 1$. Gun- nison: July 3, 1934, Z$. Estes Park, Big Thompson River: Aug. 4, 1940, T. H. Prison & T. H. Prison, Jr., 2 nymphs, 5 exuviae. Idaho.—Swan Valley, Caribou National Forest: Aug. 28, 1935, H. S. Telford, 1?. Although Claassen (1931) described and figured this nymph, but under the \A'rong name, it seems desirable here to present a new illustration of it, fig. 53, and add illustrations of the mouthparts, fig. 54. PERLODIDAE Perlodes Banks It has been my good fortune to study in considerable detail the types, or what re- mains of them, of Arcyiiopteryx vagans Smith, Arcyiiopteryx aurea Smith, Arcy- iiopteryx lineata Smith, Protarcys bradleyi Smith, Protarcys dolobrata Smith (the ne- allotype only), Dictyopteryx irregularis Banks, Dictyopteryx sigiuita Hagen, Per- lodes slossoiiae Banks, Perlodes yosemite Needham & Claassen (allotype) and Per- lodes tibialis Banks. All of these species were placed by Needham & Claassen (1925) in the genus Perlodes, and while these authors sank Protarcys Klapalek, Megarcys Klapalek and Arcyiiopteryx Klapalek as synonyms of the subgenus Perlodes, they proposed the new subgenus Perlinodes for the reception of Arcyiiop- teryx vagans. I have studied too few specimens of adults and nymphs to permit me to come to definite conclusions regarding the prop- er appraisal of the names Arcyiiopteryx, Megarcys, Protarcys, Perlinodes and Per- lodes. For the present, at least, it seems that the safest procedure is t(j follow Needham & Claassen (1925) in placing them all in the genus Perlodes and recog- nize as subgenera the other proposed units of classification above the rank of species in this family. The studies have progressed far enough, however, to indicate that much synonymy exists in the genus and that fine distinc- tions of wing venation are not reliable for species determinations. One of the outstanding features of Perlodes {s.l.}, as I recognize the genus, is the variety and character of gills. All species studied to date have the submental gills found in Isogenus and Hydroperla, and some spe- cies have additional pairs of gills in the cervical region and on the thorax. Need- ham (1933) has even described a new genus, Oroperla, with a new species called barbara, based upon the nymph, which has a row of gills on each side of the abdom- inal segments. The adult of barbara, when found, should show remnants of these gills. My conclusions to date regarding valid species and synonymy are presented under the headings of the species concerned. Perlodes minor (Klapalek) Arcynopteryx minor Klapalek (1912, p. 22). Original description, i . Pcrlodrs slossonac Banks (1914, p. 608). Original description, 9. New synonymy. 288 Ii.i.iNois Natirai. History- Survi:>- Hui.i.etix f'ol. 22. Art. 2 Anynoptiryx litiiala Smith (1917, p. 476). Original tie>cripticm, 9. New syii<»n>my. PirloJfs martjarilti Alexander (1936, p. 26). Original description, pic female of lineata (C. U. No. 1,138) and the typic Fia. 55.— PnloJrs minor. $SUBCENITAL PLATE female of .v/oy.vr„/rt(' (iVI.C.Z. No. 11,308). Certainly both of these are identical as to species. Fig. 55 is an illustration of the subgenital plate of the holotypic female described by Smith (1917) as lineata. Male and female specimens of minor determined by Klapalek are in the collec- tion of the Museum of Comparative Zo- oIojr\ . Wlien these were compared with specimens of Perlodes from Mount Wash- injiton, N. H., previously determined as lineata. and with the type of slossoiiae, no tangible differences could be found. Spe- cies of stoneflies have a much more general distribution within certain limits than lit- erature records indicate. Although I have not examined the t\ pe of maryarita 1 feel quite certain that it is the male of the spe- cies Banks described as slossonae—they even came from the same mountain — which in turn is the same species as lineata from nearby New York. On the highest mountains in the East are a few species of stoneflies found at lower levels farther north. Klapalek's minor is a species of Perlodes having a pair of gill remnants in the adult only on the submentum. In western North America there is another species of Per- lodes named amerieana (Klapalek) cIoscIn related on the basis of gills to /ninor but with a distinctive subgenital plate in the female and with different genitalia in the male. P. ignota (Smith), described (1917) without locality data, is evidently another synonym of minor, but the type could not be found when my studies of the Perlodes tjpes were made. Perlodes aurea (Smith) .Ircynopteryx aiirra Smith (1917, p. 477). Original description, 9- Ariynopteryx vayans Smith (1917, p. 478). Original description, i . New synonymy. Arcynopteryx aurea was described from a single female (C.U. No. 1,141) from "San Diego, Calif., April 23, 1879." and vagans from a single male (C.U. No. 1.139) from "California." I have studied the types of both aurea and vagans and as a result have come to the conclusion that the specimen described as vagans is the male of aurea, the name aurea having page priority. My reasons are as follows: Males and females agree- ing with these two sexes occupy the same general territory, the opposite sex of each has not been previously located, and morphologically both are unique among North American species of stoneHies in having five pairs of gill remnants, fig. 56. Fi^. 56 Perlrtdes aurea: A, female holotype from California ; B, female specimen from Oregon. An illustration of the subgenital plate of the female holotype of aurea is present- ed in fig. 56A . Fig. 56B is an illustration of the subgenital plate of a female 1 con- sider to be aurea from Oregon. The head and pronotum of aurea, as observed in an Oregon specimen, has a pattern as in fig. 56. Although Needham & Claassen (1925) mentioned the five pairs of gills in I September, 1942 Frison : North American Plf.coptera 289 quoting Smith's original description of vagal! s, reference to this feature was omit- ted when they quoted the original descrip- tion of Smith for aurea, although the lat- ter description contains such a statement. In the Illinois Natural History Survey collection are two nymphs from Rogue River, Ore., Sept. 29, 1932, collector, R. E. Dimick, which have five pairs of gills located as in the adult of aurea, and hence I consider them to be of this species. Records for the distribution of this species based upon Illinois Natural History Survey material, or the identification of specimens for others, are as follows. Oregon.—Corvallis, Alsea River: April 2, 1939, Davidson, 1$. Near Lacomb, Roaring River: March 20, 1934, R. Dimick, 1 c5 . Park- dale, east fork of Mount Hood River: May 2, 1934, R. Dimick, 16. Rogue River, 1,780 feet elevation: Sept. 29, 1932, R. Dimick, 2 nymphs. Tillamook: March 20, 1934, Joe Schuh, 1$. Washington.—Easton: April 17, 1934, G. Hoppe, 86, 2$ ; April 25, 1934, G. Hoppe, 76. Perlodes dolobrata (Smith) Protarcys dolobrata Smith (1917, p. 469). Original description, $ . Perlodes dolobrata Needham & Claassen (1925, p. 52). Description, $ . I have not studied the typic female, in the Academy of Natural Sciences of Phila- delphia, and described without locality data, and full information regarding actu- al number of pairs of gills is not given in the original description. The descrip- tion does indicate, however, that thoracic gills are present, and it is a safe assump- tion that submental gills are present, there- by making Smith's key to Protarcys in- decisive. Needham & Claassen (1925), apparent- ly on the basis of wing venation, described a male from "Glacier Peak and Lake Chelan Dist." as the "neallotype." This specimen, in the Cornell University col- lection, has a pair of submental gills and at least one thoracic pair (number of pairs doubtful because of poor condition of speci- men). Since these authors did not figure the important genital structures of this male, I am presenting illustrations of the terminal abdominal tergites, as viewed from above, and a view of the supra-anal process and Hanking lateral stylets, fig. 57. Whether this male is correctly associated with its female remains to be established by future collections. Perlodes tibialis Banks Perlodes tibialis Banks (1914, p. 608). Orig- inal description, 6 Protarcys bradleyi Smith (1917, p. 470). Original description, 6,9. New synonymy. The type of tibialis is a male (M.C.Z. No. 11,309) and is from "Ol.vmpia Mts., Wash." A study of this male reveals it has a pair of submental gills and two pairs of gills on the sides of the thorax as Smith (1917) described for Protarcys bradleyi. For some reason, Smith (1917) in her account of the North American species Fig. 58.— Perlodes tibialis c? Abdominal tergites Supra-anal process Fig. 57. — Perlodes dolobrata. ? SUBCENITAL PLATE of Perlodes failed to include any reference to the two species of Perlodes, tibialis and slossonae, described by Banks in 1914. \n the Illinois Natural History Survey collection is a male of tibialis from Fish Lake, British Columbia, July 23, 1908, which agrees in structural details with the type, and a female with the same data which agrees with the male in gill arrange- ment. It is my belief that these two speci- mens of opposite sex are of the same spe- cies. A study of the holotypic male and allotypic female of Protarcys bradleyi Smith (C.U. No. 1,135) reveals that tlie allotvpe of bradleyi, fig. 58, from "Rogers Pass,' B. C, August 7, 1908," is identical with the female in the Survey collection I consider to be the heretofore unknown female of tibialis. In general the holo- typic specimen agrees with the allotype, and the gill arrangement is identical. Un- 290 111 iNdis Natl KM. History Si'rviiv Bui.i.ktin I'ol. 12, Art. 2 fortunately, the holotypic male of brudlvy'i has its ahdomen missin}!, hut Smith's draw- inji of a side view of the para^enital plate, lateral stylets and supra-anal process of the typic male are sufficient to indicate their likeness with tibialis. In view of (1) the distrihutional ranjje involved, (2) the agreement in {^ill arranjiement, (3) the similarity of a female evidently helonging to tibialis with the allotype of bradleyi, (4) the general agreement of a drawing of certain genitalic structures of the typic male of bradhyi with the male of tibialis and (5) the overlooking hy Smith of the species tibialis when describing bradlcyi, 1 propose that bradhyi be placed in the s\ iionymy of tibialis. Perlodes signata (Hagen) Diityopteryx signata Hagen (1874, p. 575). Original description, $, 9. Ditlynpteryx Irreyularis Banks (1900, p. 243). Original description, 9- Synonym. Perlodrs yosemitc Needham & Claassen (1925, p. 56). Original description, $, 9- New synonymy. Smith (1917) placed irregularis in the synonymy of signata, but Needham & Claassen (1925) have treated the two as distinct. I have studied the tvpes of both irregularis (M.C.Z. No. 1,130, 9) and signata (M.C.Z. No. 244, i, 9) and can find no good characters for their sepa- ration. The types of both species have a distinctly cleft subgenital plate in the fe- male, and both sexes have four pairs of gills: one pair attached to submentum and three pairs on sides of thorax. The differ- ence that Needham per- haps the closest representative of the jienus Perlii as now—but probably erroneousl\— used in Europe (sense of Klapalek l^)23rt) ; (2) the recognition of Togoperla and Seophasganophora as valid North American genera ( Frison 1935rt) removed imnuiri/inata (Say), media (\\^ilker) and tdpitatti (Pictet) from the list; (3) the erection t)f the genus Hydroperla (Frison l'>35^/) removed the names of crosbyi ( Needham ^' Claassen) and varians (Walsh); (4) the placement (Frison 1035rt) of duplicata (Banks) in the genus Isoptrla; and (5) the placement of kan- stnsis (Banks) in Toyoperla (Frison 1037) removed an additional species. In this paper the list is further reduced as follows : ( 1 ) Perla sabtilosa Banks is placed in the genus Acroiwuria, and A. depressa Needham & Claassen is shown to be a synonym of it; (2) Perla posiica Walker is considered to be unrecognizable at present and siibvarians (Banks), be- longing to the genus Hydroperla, is the name to be associated with some at least of the Needham ^' Claassen records given under the name postica. It is quite evident from my studies to date that the species now left in Perla, some of which may later fall in synonymy, constitute several complexes or species groups, represented by such divergent forms as niodesta Banks, luctuosa Banks and hil'ihata Needham & Claassen. It is highly probable also that one or two of these species will in the future be shifted to such genera as Isoperla or Hydroperla, since their generic relationships are some- what obscured now because of the poor condition of the types and the lack of other material which can be definitely associated with these names. Until these species are better known, however, it seems advisable to record them all under a single generic name. In view of the fact that it now seems unwise to use the generic name of Perla for these species, and for the two new species described in this article, the prob- lem of selecting a generic name is present- ed. It is now my belief that the species duplicata placed by Banks in Perla should not be included in Isoperla, as I proposed in 1935, and that it is more closely related to the species group represented by niodes- ta Banks. This realignment of duplicata with such species as niodesta, and my pres- ent belief that the species now under dis- cussion should be grouped as a unit until they are better known, make possible the use of the name Diploperla Needham & Claassen (1925) for these species, since Diploperla was proposed for the species duplicata and bilobaia. This action is ad- vantageous in that it makes possible the use of a name already in literature and removes the controversial name of Perla. Therefore, until additional information warrants other generic treatment, 1 pro- pose to group under the generic name of Diploperla Needham & Claassen {sd.) the species described under the following names: Perla iiinubila Needham & Claas- sen, Perla alanieda N. & C, Perla expansa Banks, Isogea us hastatus Banks, Perla jugitans N. & C, Perla no/ia N. & C, Perla aestivalis N. & C, Perla niodesta Banks, Perla verticalis Banks, Perla tinc- tata Claassen {noni. nov. for tincta N. & C), Perla sorpta N. & C, Dictyogenus f phaleratus Smith, Perla niisnoma Clsn. {noni. nov. for obscura N. & C), Perla errata Clsn. {noni. nov. for venosa N. & C), Perla bilobata N. & C, Perla dupli- cata Banks, Perla luctuosa Banks and Perla raniosa N. & C. I am also assigning to this genus three new species described in this article. Since Needham & Claassen (1925) did not select a genotype for Diploperla, I designate the species hitherto known as Perla bilobata Needham & Claassen as the genotype because it is one of the two originally included species. The proper family placing of this genus has many puzzling aspects. The cleft tenth abdominal tergite, supra-anal proc- ess and associated structures in the male, as well as the wing venation and other features of both sexes, suggest a close re- lationship with Hydroperla. Lack of dis- tinct submental gills is annoying from the standpoint of a family key character, but there is a suggestion of these sub- mental gills in the small nipple-like pro- tuberance where a long submental gill is present in other genera of this family. Diploperla bilobata (Needham & Claassen) Perla bilobata Needham k Claassen (1925, p. 95). Original description, $, $. September, 1942 Prison: North American Plecoptera 303 Perla bilobata Claassen (1931, p. 54). Nymphal description. Claassen's (1931) description of the nymph of this species was based upon nymphal skins from "Old Forge, New York," and, although the mouthparts were illustrated, no illustration of the entire nymph was presented. During the course of field work near Gatlinburg, Tenn., in 1930, numerous nymphs of this species were collected and both males and females reared. Since no illustration of this nymph exists in liter- ature, fig. 74 is presented. The unusual Fig. 74.—Nymph of Diplo perla bilobata. appendage at the end of the abdomen in the nymphal male, lacking in the female, was not noted by Claassen in his descrip- tion. The mouthparts of the nymph are as in fig. 75. Fig. IS.—Diplo perla bilobata. Records for this species in the Illinois Nat- ural History Survey collection are as follows. Tennessee.—Great Smoky Mountains Na- tional Park, Gatlinburg: June 14, 1940, Frison et al., 2$, 1 exuvia, 4 nymphs; June 17, 1940, Frison ct al., 12; June 18, 1940, Frison et al., 1? with exuvia (reared) ; June 19, 1940, Frison et al., 2 2 with exuviae (reared), \ $ ; June 20, 1940, Frison et al., 12 with exuvia (reared); June 21, 1940, Frison et al., 12 with exuvia (reared) ; June 24, 1940, Frison et al., 12 with exuvia (reared), 2 2 ; Le Conte Creek, May 14, 1939, Frison & Ross, 7 nymphs; Le Conte Creek, June 14, 1940, Frison et al., 2$, 42 ; Cades Cove, June 13, 1940, Frison ct al., 1 2 with exuvia and 1$ with exuvia (reared), many nymphs; Fighting Creek Gap, May 15, 1939, Frison & Ross, 1 nymph. North Carolina.—Smokemont, Oconaluftee Creek: May 28, 1934, T. H. Frison, 1 nymph. Macon County: Big Creek above Lake Ran- dall, June 20, 1939, Thelma Howell, 1 nymph; Nantahala River, May 30, 1939, Thelma How- ell, 1 nymph. Balsam: April 24, 1938, Ross & Burks, 9 nymphs. Diploperla modesta (Banks) Perla modesta Banks (1908fl, p. 255). Orig- inal description, $ , 2 . It was my good fortune in August, 1940, while in Wyoming, to rear several male and female specimens of modesta and thus definitely associate the nymph of this species with its adult. Since the nymph has not been previously described or illustrated, at least under the name modesta, I am presenting the following description. 304 Illinois Natural History Survhy Bulletin lol. 22. Art. 2 Nv.MPH.—General color yellow or yel- lowish brown with darker areas on head. thorax and abdomen . as in fig. 76. An- tennae, legs and anal cerci mostly yel- lowish. Head with three ocelli forming an al- most equilateral triangle, the lateral ocelli about as far apart as each is distant from inner edge of compound eye; no occipital ridge ; basal segments of mouthparts con- spicuously extending far out laterally from the side of head so that head appears much broader than thorax. Labium, maxillae and mandibles as in fig. 77. Pronotum much broader than long; margins darkly bordered and central area light colored, rugosities very faint. Abdominal tergites mostly yellowish with dark transverse markings on anterior and posterior margins, fig. 76; tergites with scattered, short, stout setae. Cerci long, many segmented, segments progres- sivel> longer from base to apex, a longi- tudinal row of long, fine setae on dorsal Fi>5. 76.—Nymph of Diplopctia modesta. Fi^. 77. — Diploprrla modfsta. surface in addition to short, stout setae encircling apex of each segment. Approximately mature specimens with a body length, exclusive of appendages, of 16 mm. A small nipple-like projection at each outer posterior corner of the submentum suggestive of an atrophied submental gill. Since there are only a few records of this species in the literature, I present the follow- ing. Colorado. — Pingree Park: Aug. 15-22, 1924, Drake & Hottes, 1$. Rocky Mountain' National Park, Fall River and Olacier Creek: Aug. 15-17, 1940, T. H. Prison & T. H. Prison, Jr., 2^, 3$ (reared), 1 nymph, exuviae. Idaho.— Victor, Moose Creek: Aug. 12, 1940, T. H. Prison & T. H. Prison, Jr., \$, 19,4 exuviae. Montana.—Saltese: July 9, 1936, H. H. Ross, 1^ (reared). Silver Gate, Soda Butte Creek: Aug. 2, 1940, T. H. Prison & T. H. Prison, Jr., 4 nymphs. Oregon. — Wallowa County, Lick Creek: Aug. 12, 1937, 19. Benton County, Muddy Creek: April 12, 1938, S. G. Jevvett, Jr., 1^. Utah.—Logan Canyon: At light, July 29, 1937, Knowlton & Harmston, 36, 39 ; Aug. 1, 1937, Smith & Harmston, 1 c5 , 39; July 25, 1938, Knowlton & Harmston, 5^, 79- Washington.—Cashmere, Wenatchee River : July 10, 1936, H. H. Ross, U, 29- Wyoming. — Pahaska Tepee, north fork Shoshone River: July 29, 1940, T. H. Prison & T. H. Prison, Jr., 1 exuvia. Near Wapiti, north fork Shoshone River: July 30, 1940, T. H. Prison k T. H. Prison, Jr., 1 ,5 , 1 9 (both September, 1942 Prison : North American Plecoptera 305 reared), 4 nymphs. Yellowstone National Park, Soda Butte Creek: Aug. 2, 1940, T. H. Prison & T. H. Prison, Jr., 1^. Grand Teton National Park, Beaver Creek and Cascade Canyon: Aug. 7-9, 1940, T. H. Prison & T. H. Prison, Jr., S$, 6$ (1 reared), nymphs, exuviae. Wilson, Coal Creek: Aug. 12, 1940, T. H. Prison & T. H. Prison, Jr., 1 nymph. I have studied a nymphal male in the collection of Cornell University collected at "Estes Park, Colo., Aug. 2, 1921," which was determined as "P. expansa^ by Claassen. It is probable that this is one of the specimens he describes and records, with erroneous date citation, from "Estes Park, Col., Aug. 4, 1921," and states that "identification of this species was made possible by a study of the genitalia of both male and female nymphs." The genitalia of this male are well developed, but I cannot separate this specimen from similar well-developed nymphs which I am certain are modesta. It may be that ex- paiisa is a synonym of modesta. It is possible that the nymph described, but not reared, by Claassen (1931) as Perla expansa Banks [now Diploperla ex- pansa (Banks)] is of this species. This possibility is suggested because of the unidentate character of the lacinia. Diploperla pilata new species Male. — General color yellowish to dark brown. Head and pronotum with dark and light areas forming a color pat- tern as in fig. 78. Legs, antennae and anal cerci yellowish brown. No gill rem- nants. Head wider through compound eyes than width of pronotum ; lateral ocelli slightly more removed from one another than from anterior ocellus, distance be- tween them about twice the distance each is removed from inner edge of compound eye. Pronotum approximately quadrangular, somewhat broader than long, angles rounded, a distinct pattern of raised rugos- ities on surface each side of median longi- tudinal stripe, fig. 78. Legs with first and second tarsal seg- ments together about one-third as long as third, first tarsal segment slightly longer than second. Wings, fig. 78, essentially hyaline with venation dark brown ; tip of wing with branches of radial sector slightly turned upwards; venation in general similar to that of wing figured for Dictyopterycjella knowltoni Frison (1937). Abdomen, fig. 78, with tenth tergite cleft for reception of narrow, elongate, supra-anal process, membranous on upper surface and sclerotized on lower surface, flanked on each side by a slender, sclero- tized, lateral stylet (paragenital lobe) ; dorsal lobes on posterior margin of seg- ment bordering cleft shaped as in fig. 78, with some short, stout spines. Seventh sternite, fig. 78, with a broad lobe extend- ing slightly backwards, ninth sternite pro- duced backwards over tenth sternite but not upturned over tenth sternite. Length to tip of wings 16 mm.; length to tip of abdomen 13 mm. Female.—Head, thorax, basal abdom- inal segments and appendages in general similar to those of male but slightly larger in size. Important dift'erences are as fol- lows: eighth abdominal sternite, fig. 78, with subgenital plate greatly produced so that it covers most of the ninth sternite, hind margin of plate not indented, sides somewhat rounded. Holotype, male.—Vedder Crossing, B. C : May 10-26, 1936, W. E. Ricker. Allotype, female.—Same data as for holo- type. Paratypes. — British Columbia. — Vedder Crossing: Same data as for holotype, 3 5, 17$; Chiliiwack River, April 24, 1937, S. Spencer, \$ ; May 9, 1937, Ricker & Spencer, 7 (J, 3$. SuMAs River: May 4-6, 1937, W. E. Ricker, 2$. Cultus Lake: May 10-26, 1937, W. E. Ricker, \$, 1$; Chiliiwack River, May 8-22, 1938, S. Spencer, 29- Oregon.—Dodge Park, at confluence of Sandy and Bull Run rivers: June 22, 1933, R. Dimick, 1$. Lacomb, Crabtres County: June 4, 1935, R. Dimick, H. Clackamas County, Eagle Creek: June 20, 1935, S. G. Jewett, Jr., 8?. Parmer's River: June 20, 1930, 1$. Prospect: July 12, 1933, G. Hoppe, 1$. Washington.—Green River Gorge: May 27, 1933, G. Hoppe, 1 c5 . Nymfh. — General color yellowish brown with darker areas on head, thorax and abdomen, as in fig. 79. Antennae, legs and anal cerci mostly yellowish. Head with three ocelli forming an al- most equilateral triangle, lateral ocelli about as far apart as each is distant from inner edge of compound eye ; no occipital ridge ; basal segments of mouthparts con- spicuously extending out laterally from the sides of head so that head appears much broader than thorax. Ulb Illinois Natlrai. Historv Slrnin Hii.lktin lol. 22. Art. 2 Labium, maxillae and mandibles as in Hg. 7S. A small, nipple-likc projection at each outer posterior corner of the submentum >u^:j:estive of an atrophied submental gill, fig. 7S. No true submental gill. Pronotum much broader than long; outer margins darkly outlined and central area mostly light colored, raised rugosities faint. Abdominal tergites mostly yellowish brown with narrow, dark, transverse stripes prominent on anterior margins and weaker on posterior margins, fig. 79; ter- gites, except for posterior margins, mostly devoid of short, stout setae. Cerci long, many segmented, segments progressiveh longer from base to apex; a longitudinal row of long, fine setae on dorsal surface in addition to smaller spinelike ones en- circling apex of each segment. 9 SuBGENITAL PlATE 9 Head and Pronotum Supra-anal process Fig. 78.—Diplopcrla pilata. September, 1942 Frisox : North American Plecoptera 307 V Fig. 79.—Nymph of Diploperla pilata. Approximately mature specimens with a body length, exclusive of appendages, of 17 mm. Nymphal and exuvial records are as fol- lows: SuMAS River, British Columbia, May 4-6, 1937, W. E. Ricker, 3 nymphs, 1 exuvia. I am naming this species as new with considerable misgiving because of its close relationship with Diploperla expansa (Banks), described from Colorado; fu- ture collecting and studies may determine that they are synonymous. D. expansa is represented in the Illinois Natural His- tory Survey collection by two females from separate localities in Colorado. These differ from the specimens here described as new in having a much larger and more quadrate subgenital plate; also, there are some differences in the color pattern on the head. Furthermore, Claassen (1931) de- scribed, but did not figure, the n\mph of expansa as having the lacinia unidentate and similar to D. bilobata (Needham & Claassen). The nymphs described here, and which I am certain go with the adults here described, have the lacinia bidentate. If Claassen's association of the nymph with expansa is correct, then this proposed new' species is certainly distinct. There is a possibility, however, since Claassen did not actually rear any specimens of expansa from the nymphs he describes, that nymphs he called expansa are D. uiodesta (Banks) or some other closely related species. Diploperla bulbosa new species Male. — General color yellowish brown. Head and pronotum with dark and light areas forming an indistinct pat- tern, as in fig. 80. Legs and antennae in general concolorous with head and thorax ; anal cerci with apical segments more yel- lowish. No gill remnants. Head through compound eyes about as wide as pronotum ; lateral ocelli slightly more removed from one another than from anterior ocellus, distance between each lat- eral ocellus and inner margin of compound eye about equal to distance between lateral ocelli. Pronotum approximately quadrangular, somewhat broader than long, a pattern of raised rugosities on surface each side of rather indistinct, median, longitudinal, yel- lowish stripe, fig. 80. Legs with first and second tarsal seg- ments together about one-half as long as third, first tarsal segment slightly longer than second. Wings with membrane and veins heav- ily stained with brown ; venation of holo- type as in fig. 80, but no doubt subject to some variation in a series of specimens. Abdomen with segments normal through ninth; tenth tergite cleft, fig. 80, the lobes formed by this cleft raised up- wards ; supra-anal process erect and pro- truding with tip bulbous, inclosed at base by two weakly sclerotized lobes or mem- branous folds; without lateral stylets flanking supra-anal process ; subanal lobes elongated, somewhat bulbous at tip and forming a back support for supra-anal process. Seventh sternite with a broad lobe on posterior margin ; eighth sternite with slight indications of a lobe, accentuated by the more numerous concentration of hairs, fig. 80. Length to tip of wings 14 mm.; length to tip of abdomen 18 mm. 308 Iii.iNois Natlrau History Survey Bulletin lol. 22, Art. 2 Abdominal segments^ Fig. HO.—Diplopcrla buibosa. Female,—Head, thorax, basal abdom- inal segments and appendages in general similar to those of male, but slightly larger in size. Important differences are as fol- lows: Eighth abdominal sternite on pos- terior margin with a very large subgenital plate which covers most of the ninth ster- nite ; median posterior margin of this plate is distinctly cleft, fig. 80. Holotype, male.—Great Smoky Mountains National Park, Oreenbricr Cove, Tenn.: June 4, 1939, A. C. Cole. Allotype, female.—Same data as for holo- type. Paratypes. — Tennessee.—Gatmnburc: June 27, 1940, reared from nymph, T. H. Prison ft al., 1 $ . Nymph. — General color yellowish brown with dark brown or fuscous areas on head, thorax and abdomen, as in fig. 81. Antennae, legs and anal cerci mostly yel- lowish brown. Head with three ocelli forming an al- most equilateral triangle, lateral ocelli slightly closer together than each ocellus is distant from inner margin of adjacent compound eye ; no complete occipital ridge, but short, stout spinulae with conspicuous bases extend around posterior half of com- pound eye, and a row of them extends in- wards part way to center from inner mar- gin of each compound eye ; basal segments of mouthparts extend out conspicuously from sides of head so that head appears much broader than pronotum. Labium, maxillae and mandibles as in fig. 80 ; glossae and paraglossae terminating in nipple-like structures. Pronotum broader than long, posterior angles or corners more rounded than an- terior angles, fig. 81. Abdominal tergites with prominent, pale-colored spots surrounded by dark brown or fuscous, fig. 81. Cerci long, many segmented, segments progressively longer from base to apex ; a longitudinal row of long, fine setae on dorsal surface in addition to smaller spinelike ones en- circling apex of each segment. Approximately mature specimens with a body length, exclusive of appendages, of 14 mm. A small nipple-like projection at each outer posterior corner of submentum is suggestive of an atrophied submental gill. Xo true submental gill. Nymphal and exuvial records are as fol- lows. September, 1942 Prison : North American Plecoptera 309 North Carolina.—Small stream near New- found Gap, 3,560 feet elevation: May 28, 1934, T. H. Prison, 1 nymph. Smokemont, Oconaluftee River: May 28, 1934, T. H. Prison, 2 exuviae. Macon County, Nantahala River: May 30, 1939, T. Howell, 1 nymph. Tennessee.—CJatmnburg: June 13, 1940, T. H. Prison ft al., 1 nymph, 6 exuviae. Fig. 81.—Nymph of Diploperla hulbosa. This new species is close to the complex of species typified by Diploperla hastata (Banks). It differs from hastata in the male in the shape of the supra-anal process and the lack of lateral stylets or para- genital plates and in the female in the shape of the subgenital plate. The nymph is apt to be confused with the nymph of hastata, but the large light-colored areas on the abdominal tergites present in this new species are lacking in hastata. Diploperla arina new species Male. — General color yellow and brown. Head and pronotum with brown and yellow areas forming a color pattern as in fig. 82. Legs yellow with brown markings; antennae and anal cerci yel- lowish brown. No gill remnants. Head wider through compound eyes than width of pronotum; lateral ocelli slightly more removed from one another than from anterior ocellus, distance be- tween them about the same as each is distant from inner margin of adjacent compound eye. Pronotum approximately (]uadrangular, V" Nymphal Mandibles ities on surface each side of pale, median, lonjiitudinal stripe, with pos- terior end of stripe broader than anterior end. fig. 87. Legs with first and second tarsal seg- ments together shorter than third, first tarsal segment longer than second. Wings h\aline with costal margins pale yellowish, venation light brown. Abdomen, fig. 87. with tenth tergite not cleft but with a distinct, depressed, median, longitudinal trough almost free of stout setae and separating flanking patches of numerous short, stout setae ; subanal lobes recurved upwards over tenth tergite and with prominent, slender, long, sharply pointed tips; aedeagus membran- ous with distinctive shape, tig. 87 ; ninth sternite produced much beyond tip of abdomen and rounded behind ; eighth ster- nite with a prominent median lobe on posterior margin, fig. 87. Length to tip of wings 10 mm.; length to tip of abdomen 9 mm. Fem.ale.—Head, thorax, basal abdom- inal segments and appendages in general similar to those of male but slightly larger in size. Important differences are as fol- lows : eighth abdominal sternite, fig. 87, with subgenital plate partly produced over ninth sternite and deeply notched in most specimens but occasionally only slightly indented. Holotype, male.— Spearfish, Spearfish River, S. I).: July 27, 1940, T. H. Prison & T. H. Prison, Jr. Allotype, female.—Same data as for holo- type. Paratypes. — South Dakota. — Spearfish : Same data as for holotype, 45,^, 20$. British Columbia.—Vancouver: July 25, 1936, H. H. Ross, 1$. California.—Mono County, Convict Creek: July 3, 1938, H. J. Rayner, 2$. Colorado.—Hartzel: July 22, 1938, H. H. & J. A. Ross, 1$, Iola: June 22, 1934, ele- vation 7,450 feet, H. Pratt, 2$. Eckert, Surface Creek: June 28, 1938, Lanham & Bauer, 29. CjRANby, Colorado River: Julv 24. 1938. H. H. & J. A. Ross, 3$. Lake C;eorge, South Platte River: Julv 22, 1938, H. H. & J. A. Ross, 1$. Idaho.—St; Anthony: June 28, 1938, H. S. Telford. 19. Montana.—Harrison : July 8, 1936, H. H. Ross, 19. TosTON, Missouri River: June 22, 1940, H. H. & J. A. Ross, IS i , 15 9. NoxON, Clark Fork River: June 23, 1940, H. H. & J. A. Ross, 16. Oregon. — Frenchclen, Harney County, Blit/en River: July 11, 1935, S. G. Jewett, Jr., 1 c^ . Five miles south of Union Creek on Mill Creek: June 24, 1937, S. C. Jewett, Jr., 1(5. Port Klamath: June 26, 1937, S. G. Jewett, Jr., 3 <^ , 19. Willamette River: Mav 26, 1938, C. Jensen, 1,5, 19. Near mouth of Williamson River, July 8, 1938, R. Dimick, 19. Utah.—Ogden Canyon: June 21, 1937, O. E. Hardy, 1 9 ; June 23, 1938, Hardy & Stains, li. Blacksmith Pork Canyon: June 20, 1937, Harmston & Smith, 8,^, 69. Hunts- ville; June 23, 1938, Hardy & Stains, 19; June 27, 1937, G. F. Knowlton, 19. Sunset: Julv 26, 1933. G. P. Knowlton, 19. Paradise: June 14, 1938, Hardy & Stains, Ui, 12 9- Kanosh Canyon: May 27, 1939. Knowlton & Harmston, 1 c5 , 3 9. Eden: Julv 15, 1938, G. P. Knowlton, 19- Uinta: June 18, 1937, G. F. Knowlton, 2(5, 29- Logan Canyon: July 11, 1938, D. E. & A. T. Hardy, 19. Smithfield: May 13, 1939, Knowlton & Harm- ston, 29. Wyoming. — Boulder, Tributary of Pine Branch: July 6, 1936, H. H. Ross, 3$, 29- Pinedale, Green River: July 6, 1936, H. H. Ross, 19. Centennial: July 2, 1938, D. J. & J. N. KnuU, 19. Nymph.—General color pale yellow- ish with darker areas on head, thorax and abdomen, as in figs. 88 and 89 ; speci- mens exhibit color variation from a light, fig. 88, to dark, fig. 89, phase; nymphal male in life sometimes shows reddish ab- dominal coloring as in adult. Antennae, legs and anal cerci mostly yellowish. Head with three ocelli forming an al- most equilateral triangle, lateral ocelli about as far apart as each is distant from inner edge of compound eye ; no occipital ridge ; basal seginents of mouthparts not extending out from side of head. Labium, maxillae and mandibles as in fig. 87. Pronotum broader than long, with markings as in figs. 88 and 89. Abdominal tergites with general back- ground yellowish and with dark longi- tudinal stripes as in figs. 88 and 89 ; some scattered, stout, short setae on abdominal tergites in addition to row on posterior margin of each tergite. Cerci long, many segmented, segments progressively longer from base to apex ; a longitudinal row of long, fine setae on dorsal surface of apical segments in addition to smaller spinelike ones encircling apex of each segment. Approximately mature specimens with body lengths, e.xclusive of appendages, in males 11 mm. and in feinales 12 mm. September, 1942 Frison : North American Plecoptera 315 No thoracic, anal or submental gills. Nymphal and exuvial records: same data as for holotype, 22 nymphs, 13 exuviae. I am naming this species in honor of my daughter, Patricia Ann, who takes great delight in assisting with the collec- tion of stonefly adults and nymphs when- ever opportunity presents itself and who but the subgenital plate of the female is quite different, and the subanal lobes of the male are much shorter and stouter. Fig. 88. -Nymph of Isoperla patiicia, light form. helped with the collection of the nymph and adult specimens from Spearfish, S. D. This widely distributed western species is easily recognized in the female among species of Isoperla, because of its usually distinctly notched subgenital plate and the peculiar darkening of the posterior part of the mesothorax and metathorax. Iso- perla fulva Claassen (1937^) has some- what the same general color appearance, Fig. 89.—Nymph of Isoperla patricia, dark form. /. externa Claassen (1937t'rl(i transnuiriiia was synonyniized In Hajioii in ISOl as the same as hilineata (Say). Init Ricker (1938) has clearly shown that it is not hilineata. Kicker's drawings of the color pattern of the head and of the subfjenital plate are so charac- teristic of ventralis that I have no hesi- tancy in placinji ventralis as a synonym of transmarina. Newman's original description is not clear as to sexes involved, but according to Ricker the typic specimen now in the Hritish Museum is a female. "Inhabits Canada, etc." and "Trenton Falls" indi- cate in the original description the source of the typic specimen, and the specimen considered as the type by Ricker is from 1 / ^ / "North America." The statements re- garding locality »)f typic specimen fit the general northeastern range of the species described by Banks (1908/>) as ventralis and now synonymized as transmarina. Isoperla i-entralis was described from specimens collected at "Grand Lake, New- foundland," and the typic series is now in the collection of the Museum of Compara- ti\e Zoology (No. 11,333). In the orig- inal description, reference is made to both males and feinales, but the typic series Nymphal Maxilla Fiii. 90.—Nymph of Isoperla transmarina. Fig. 91. — Isoperla transmarina. now contains only males. Evidently a similar situation existed when Claassen studied the types, because Needham & Claassen (1925) omit any reference to the female. Through the kindness of Dr. Nathan Banks, 1 was permitted to relax one of the typic males and study it closely in com- parison with reared specimens. It seems advisable to designate this particular speci- men as the lectotype and I so do. The rearing of adult males and females has enabled me to associate conclusively the heretofore undescribed nymph of this species, and the description of the nymph is therefore presented. Nymph.—General color yellowish with darker areas forming a conspicuous pat- tern on dorsum of head, thorax and ab- domen, fig. 90. Antennae, legs and anal cerci mosth yellowish. Head with three ocelli forming an al- most equilateral triangle, lateral ocelli about as far apart as each is distant from inner edge of compound eye ; no occipital ridge ; basal segments of mouthparts not extending out from sides of head. Labium and maxillae as in fig. 91. Pronotum much broader than long with Septc 1942 Frison : North American Plecoptera 317 markinjis as in fig. 90, corners rounded. Abdominal tergites with alternating longitudinal stripes of jellow and brown, fig. 90. Cerci long, many segmented, seg- ments progressively longer from base to apex ; a longitudinal row of long, fine setae on apical segments in addition to smaller spinelike ones encircling apex of each seg- ment. Mature specimens with a body length, exclusive of appendages, up to 14 mm. No gills present. Since this species has been previously re- corded only in the original descriptions already noted, I present the following records, which show it has a wide northeastern distribution in North America. Manitoba.^Churchill: July 5-9, 1936, H. E. McClure, S$, 3$; July 23, 1936, H. E. McClure, 1^. Swan River, Swan River: June 5, 1936, H. E. McClure, 1 <$ , 2$, 4 nymphs. Michigan.—Baldwin, Pere Marquette Riv- er: May 28, 1939, Frison & Ross, \i ; May 9, 1940, Frison & Ross, 1^, 5$ with exuviae (reared) ; same except May 9-10, $ $, $ $, nymphs, exuviae; same except May 10, \$, 19 with exuviae (reared). Boardman River, 3 miles above Traverse City power dam: March 7, 1935, J. W. Leonard, nymphs and 1 exuvia. Germfask, Manistique River: May 11, 1940, Frison & Ross, 4 nymphs. Grand Traverse County, Boardman River: May 7, 1935, J. W. Leonard, $ $, $ $. Honor, Platte River: May 27, 1939, Frison & Ross, 3 <5 , 49, 2 nymphs with exuviae and 1 $ with exuvia (reared); May 10, 1940, Frison k Ross, 2i, 6 nymphs, 1 exuvia. Lake County, Pine River: May 14, 1938, O. H. Clark, 19 ; May 16, 1938, O. H. Clark, 2 9 ; Walker Bridge Camp, May 29, 1938, J. W. Leonard, 1 <$ , 2 9 ; May 30, 1938, O. H. Clark, 19; Walker Bridge Camp, at light. May 31, 1938, O. H. Clark, 3 c?, 19; June 4, 1938, J. Blue, 1 <5 , 19; June 11, 1938, R. Love, 19; June 12, 1938, J. Blue, 3 9- Luzerne, east branch of Big Creek: J. W. Leonard, 1 exuvia. May- field, Boardman River: May 28, 1939, Frison & Ross, 1 9 • Montmorency County, Hunt Creek: April 14, 1939, J. W. Leonard, 2 nymphs. Route 46 between Muskegon and Kent City, tributary of Black Creek: May 9, 1940, Frison & Ross, 1^ with exuvia (reared), 5 nymphs. Nahma Junction, Stur- geon River: May 12, 1940, Frison & Ross, nymphs; same data except May 15, 2 9 with exuviae (reared); same data except May 17, 19 (reared) ; same data except May 20, 2 9 with exuviae (reared). Nirvana, Sanborn Creek: May 10, 1940, Frison k Ross, 4 nymphs. Otsego County, west branch of Sturgeon Riv- er: March 15, 1935, J. W. Leonard, 3 nymphs. Peacock, Little Manistee River near town: May 10, 1940, Frison & Ross, 1$, 29, nymphs, 1 exuvia. Sturgeon River, west branch be- tween Vanderbilt and Wolverine: March 15, 1935, J. W. Leonard, 1 nymph. Thompson, creek near town: May 12, 1940, Frison k Ross, 2 nymphs. Minnesota. — Winona County: May 20, 1938, Page Nicholson, 19. Ontario.—Algonquin Park, Costello Lake, Ontario Fisheries Research Laboratory: June 14, 1938, W. M. Sprules, 19. Kenora: June 16, 1908, 19. Wisconsin.—Boulder Junction: Trout Riv- er, July 3-4, 1933, Frison & Mohr, exuviae; Trout River, June 20, 1934, Frison k Mohr, 4 exuviae; Trout River, April 8-9, 1937, Frison & Mohr, 1 nymph; May 6-17, 1937, Frison k Mohr, 5 nymphs; May 7-17, 1937, Frison k Mohr, \2$, 15 9 (reared) ; May 20, 1937, Frison & Mohr, 2 nymphs. Spooner, Namakagon River: June 6, 1936, Frison & Ross, 2 exuviae. Isoperla fusca Needham & Claassen Isoperla fusca Needham & Claassen (1925, p. 146). Original description, $, 9- Specimens of this species, recorded only once (Neave 1929) since it was first de- scribed from specimens collected at Water- ton Lakes, Alberta, Canada, were found "^ y^^^.^ Fig. 92.—Nymph of Isoperla fusra. 318 IiiiNois Naiirai. History Sirvi;\- Bii.i.ktin lol. 22, Art. 2 by the writer in a Muall striMin at Dun- raven Pass, Mount Washburn. Yellow- stone National Park, Wyo., Auj::. 2. HHO. In addition to five male and two female adults, two nymphs and one exuvia were a)llected under such conditions that I am certain these immature forms belong with the adults. A nymph is shown in fig. 92. The adults agree very well with the original ilescription and a dissection of the apical abdominal sternite of one male re- vealed the forked chitinous process of the aedeagus which is so characteristic of this species and was illustrated by Needham & Claassen. Several illustrations of im- portant structures of the male and female are presented to aid future recognition of this little known species, fig. 93. cfAbdominal sternites d" Abdominal tergites Fig. 93. — Isoperla fusca. Since the n\mph has not been previous- ly recognized, a description and illustra- tion of it are presented here. NvMFH. — General color brown with lighter areas as in fig. 92. Legs, antennae, anal ccrci and ventral parts of body pale yellow. Short, stout, spinelike setae, in addition to longer hairs, present on bod\ and particularly femora. Ocelli in same relative position as in adult. Basal seg- ments of mouthparts not extending notice- ably from the sides of the head. Labium, maxillae and mandibles as in fig. 93. Pronotum broader than long with a pale vellow longitudinal stripe in middle, fig. '93. Abdominal tergites mostly dark brown, but a pale median longitudinal stripe is present, and a lateral flanking stripe on each side is slightly in evidence. Cerci long, many segmented, segments progressively longer from base to apex ; small, stout, spinelike setae encircling apex of each segment, but with no evidence of long, fine setae on dorsal surface of apical segments as in some species. Approximately mature specimens with a body length of 10 mm. No thoracic, anal or submental gills. Nymphal specimens collected at same time and place as adults. Isoperla longiseta Banks Isoperla longiseta Banks (1906<-, p. 337). Original description, $. Isoperla longiseta is a species apparently associated with the prairie and plain states mostly west of the Mississippi River and partialis replaced in the Rocky Mountain and perhaps entirely in the West Coast states by nioriiiona Banks. The collection of specimens of this species in Missouri by Dr. H, H. Ross in 1937 and the determi- nation as this species of material from Ames, Iowa, in 1935, indicated it might some day be found in western Illinois. This supposition was confirmed in 1939 by the capture in extreme western Illinois, on the Mississippi River at Quincy, of a single female of this species. I am inclined to believe that the record of longiseta from "Indiana" by Needham & Claassen ( 1925) was in error. The two typic females. No. 11,336, in the collection of the Museum of Compara- tive Zoology, have been studied and com- September, 1942 Frison : North American Plecoptera 319 pared with similar specimens in the Illi- nois Natural History Survey collection. In many respects longiseta is closely re- lated to morviona. The only characters which I have been able to locate to sepa- rate these two species are as follows : ( 1 ) in the male of longiseta the lobe on the posterior margin of the eighth abdominal sternite is rounded, figs. 94 and 95, and the subanal lobes at the tip of the abdomen are long and slender; whereas in the male of mortiiona the lobe is more distinctly truncated or square and the subanal lobes are shorter and somewhat stouter; (2) in the female of longiseta the subgenital plate, figs. 94 and 95, is much produced, rounded and strongly sclerotized, whereas in the female of morniona it is much less produced and more weakly sclerotized ; (3) in longiseta, both sexes, the pronotum has dark brown embossings that are more or less strongly contrasting in color with the remainder of the pronotum, figs. 94 and 95, whereas in mormona the entire area, except for the median yellowish stripe, is more uniformly suffused with brown. In the Illinois Natural History Survey collection is a series of males, females and exuviae from El Paso, Tex., which I am identifying with some hesitation as longi- seta. All of the males of this series are brachypterous, fig. 96. Compared with longiseta specimens from Illinois and other states, fig. 95, these Texas specimens have the dark area on the dorsum of the head anterior to the ocelli more suffused, fig. 94, and the modified subanal lobes appear shorter and stouter and in this respect Abdominal segments 2 Subgenital plate d" Abdominal TERGiTEs Fig. 94. — Isoperla longiseta, drawn from Texas specimens. Fig. 95. — Isoperla longiseta, drawn from Mississippi River valley specimens. 320 li.i.iNois Natlrai. History Survky Hui.i.etin lol. 22. Art. 2 Fig. 96. — Isnperla Innyisrta, adult male from Texas. more like nionnona. The other characters of these Texas specimens, and, particular- ly, the shape of the subfjenital plate of the female, strongly support, however, their specific identity with longiseta. The Illi- nois Natural History Survey collection also contains a single male from "La Veta Pass, Colorado," which apparently agrees with the Texas specimens in every w'ay. The n\ niph of this Texas race, as I now consider it, of lonyiseta is typical of the Isoperia group or complex containing the species hilineata (Say). Fig. 94 shows the shape of the mandibles, maxillae and labium, and fig. 97 is a dorsal view of the nymph, all drawn from exuviae. The nymph of typical longiseta from other states has not been described or illustrated, and when found it should help clear up the status of these Texas specimens. Distributional records for longiseta based upon specimens in the Illinois Natural History Survey collection, or submitted for identifica- tion, are as follows. Illinois.—Quincy: June 8, 1939, Burks & Kie^el, 1$. CoLORAno.—La Veta Pass: July 21, 1938, D. J. & J. N. Knull, 1^ (brachvpterous). Iowa.—Ames: May 30, 1929, {$, 1 9 ; June 1, 1929, 2 9 ; June 3, 1929, 1$, 19 ; June 10, 1931, P. A. Moore, 3 9. Minnesota.—St. Paul, University Farm at light: June 16, 1933, A. A. CIranovsky, 19- Missouri.—Jefferson City: May 29, 1937, H. H. Ross, \i, 19. Montana. — Glendive, Yellowstone River: July 14, 1940, J. A. & H. H. Ross, 3^, 79- Fig. 97.—Isoperla lotigiscta nymph, drawn from exuviae collected in Texas. LoiiMAN, Milk River: July 13, 1940, J. A. & H. H. Ross, 2 9 . Wolf Point, Missouri River: July 14, 1940, J. A. & H. H. Ross, 26, 99. South Dakota.—Brookings: 19; June 6, 1919, H. C. Severin, 1^. Buffalo: June 19, 1925, H. C. Severin, \$, 19- Chamberlain, Missouri River: June 19, 1940, J. A. & H. H. Ross, 6^, 3 9. Grass Rope: June 24, 1931, H. C. Severin, M, 19- Newell: June 19, 1923, H. C. Severin, 1^. Springfield: June 15, 1928, H. C. Severin, 19- Yankton: June 18, 1930, G. I. Gilbertson, 2$, 49; June 25, 1934, H. C. Severin, 29. September, 1942 P'rison : North American Plecoptera 321 Texas.—El Paso: April 22, 1939, J. A. & H. H. Ross, 8c5 (brachypterous), 5$, 3 exuviae. Wyoming. — Madison Junction, Yellow- stone National Park, Gibbons River: July 8, 1936, H. H. Ross, 19. Pinedale, Green River north of town: July 6, 1936, H. H. Ross, 1(5. Upton: June 20, 1940, J. A. & H. H. Ross, 2$, 1 ? . Isoperla mormona Banks Isoperla mormona Banks (1920, p. 322). Original description, $ . Isoperla insipida Hoppe (1938, p. 157). Original description, $, ?. New synonymy. This species is apparently closely re- lated to longiseta Banks, as mentioned in the discussion of that species. The type, a single female, No. 10,822, from "Vine- yard, Ut.," in the collection of the Mu- seum of Comparative Zoology, has been studied and compared with specimens in the Illinois Natural History Survey col- lection. Also, through the kindness of Professor Trevor Kincaid of the Univer- sity of Washington, I have had the oppor- tunity of studying the holotype and allo- type of insipida, as well as most of the paratypic specimens. I find them all to be synonymous with mormona, which is apparently a Rocky Mountain and West Coast species, meeting with longiseta in such states as Wyoming and Montana. Records for this little-known species con- tained in the collection of the Illinois Natural History Survey or identified for others are as follows. Arizona.—Coconino County, Oak Creek at Indian Garden: June 13, 1937, Leonora K. Gloyd, 4c5, 3$. Montana.—Toston, Missouri River: June 22, 1940, H. H. & J. A. Ross, Z$, 7$. Oregon.—Benton County, Oak Creek: R. E. Rieder, 1 from abdomen much as in truncata Frison. Length to tip of wings 1 1 mm. ; length to tip of abdomen 7 mm. Mali:.— Head, thorax and basal ab- dominal segments in general similar to those of female, but slightly smaller in size. Important differences or structures are as follows: tenth tergite not cleft, fig. 100, subanal lobes weakly developed and but slightly visible from above; ninth sternite, fig. 100, produced backwards so that apical tergites are not visible in ventral view; eighth sternite with a shal- lowly recessed but distinct lobe in middle of posterior margin. Holotype, female. — Ciatlinburg, Le Coiite Creek, Tenn. : reared from nymph, May 14, 1939, T. H. Frison & H. H. Ross. Allotype, male.—Same data as for holo- type. Paratypes. — Tf.nnf.ssee.—Gatlinburg: Same data as for holotype, 5$ ; same data as for holotype except not reared, 5 c? , 18$ ; June 14, 1940, T. H. Frison rt al., 1$, reared from nvmph; same data except not reared, 16 9 ; fork of Little Pigeon River, May 27, 1934, T. H. Frison, \i, 4$; Fighting Creek Gap, Mav 15, 1939, T. H. Frison & H. H. Ross, 1^, 2$.' Elkmont, June 13, 1940, T. H. Frison rl al., 19. New York.—Keene, tributary of Sable Riv- er: June 20, 1941, T. H. Frison & H. H. Ross, 3 (^ , 49. EuBA Mills, Adirondack Park: June 20, 1941, T. H. Frison & H. H. Ross, \i, 19. Hawkinsvii.le, Black River: June 19, 1941, T. H. Frison & H. H. Ross. New Hampshire. — Bentos, Witcherville Brook: June 21, 1941, T. H. Frison & H. H. Ross, 12 6, 3 9. Norrn Carolina.—Smokemont, Oconaluftee River: May 28, 1934, T. H. Frison. Pennsylvania.— Swiftvvater, Monroe Coun- ty : 1928, F. R. Nevin, 2 9 (A.N.S.). Vermont. — Topsham, Waits River: June 21, 1941, T. H. Frison k H. H. Ross, 1$. Nymph.—General color yellow with dark markings on dorsuin of head, thorax and abdomen, fig. 101. Legs, antennae and anal cerci dominantly pale yellow. Short, stout, spinelike setae, in addition to longer hairs, present on body and legs but bases not conspicuous as in such spe- cies as decepta Frison and dicala Frison, the latter described in this paper. Ocelli in same relative position as in adult. Basal segments of mouthparts not extending out from sides of head. Labium, maxillae and mandibles as in fig. 100. Pronotum broader than long with dark markings on disk, as in fig. 101. Longitudinal dark stripes on abdominal September. 1942 Prison: North American Pi,l:coptera 325 tergites tend to be connected on hind mar- gin of segments by narrow transverse line which gives tergites somewhat the appearance of having cell-like light spots each side of median, longitudinal stripe. Cerci long, many segments, progressive- 1\' longer from base to apex, a longitudinal row of long, fine setae on dorsal surface of apical segments in addition to smaller, stout, spinelike ones encircling apex of each segment. Approximately mature specimens with a body length of 8 mm. No thoracic, anal or submental gills. Nymphal records are as follows. Tennessee.—Gatlinburg, Le Conte Creek: May 14, 1939, T. H. Prison & H. H. Ross, 2 nymphs, numerous exuviae. West of Ozone: Fig. 101.—Nymph of Isoperla orata. May 15, 1939, T. H. Prison & H. H. Ross, 4 exuviae. Elkmont, Little River: Mav 14, 1939, T. H. Prison & H. H. Ross, 9 exuviae. North Carolina.—Smokemont, Oconaluftee River: May 28, 1934, 10 nymphs. This is another species belonging to the group or complex of Isoperla species con- taining biliiieata (Say). The shape of the dark area connecting the lateral and medi- an ocelli is very suggestive of truncata Frison, but the color pattern of the nymph and the much broader subgenital plate of the adult female indicate it is a distinct species. That the two species may occur in the same territory, at least in northern states, is shown by the collection of adult females of both truncata and this new spe- cies at Hawkinsville, Black River, N. Y., June 19, 1941 (T. H. Frison & H. H. Ross). Apparently truncata is most abun- dant in the north central states region and this new species in mountainous areas of the eastern states. Isoperla siniilis (Hagen) Perla similis Hagen (1861, p. 26). Original description, $ . This species was originally described from the female and recorded from "Penn- sylvania and Maryland." A single female typic specimen from "Pennsylvania — Uhler— 1858" is in the collection of the Museum of Comparative Zoology (Type No. 250) and has been compared with reared material in the Illinois Natural History Survey collection. Needham & Claassen (1925) gave additional distribu- tional records from New Hampshire and New \ork and described the previously unknown male, but did not figure any of the important structural features of the adults. Claassen (1931) gave a brief verbal description of the nymph based upon a male nymphal skin from which the adult was reared. Evidently this nymphal skin did not show the distinctive color pattern of the nymph, which is somewhat sug- gestive of Diploperla hastata (Banks) ; at least it was not noted. The pale, longi- tudinal stripe down the middle of the otherwise brownish abdominal tergites. coupled with the color pattern of the head, helps to recognize this species, fig. 102. The maxillae, mandibles and labium of the nymph are as in fig. 103. To aid with the future identification '^2b Illinois Natural History Survi;y Huli.ktin lol. 22, Art. 2 1934, T. H. Prison, 1^, 1 nvmph ; Little PJKeon River, June 13, 1935, H. H. Ross, H. Pennsylvania.—Swiftwater, Monroe Coun- ty: 1928, F. R. Ncvin, Lot 258, 19. Tennessee.—CIatlinburg: Le Conte Creek, May 14, 1939, Prison & Ross, 9 exuviae; March 24, 1940, Prison, Mohr & Hawkins, 1 nvmph; June 13. 1940, T. H. Prison rt al., 4-'6 , 3 9 ; Le Conte Creek, June 14, 1940, T. H. Prison rt al., exuviae. Newfound CJap, Little Pigeon River: May 14, 1939, Prison & Ross, 19 (reared), $S, 69, 4 nymphs, Nymphal Mandibles -4 V J I'ig. 102.—Nymph of Isopcrla similis. of the adults of this species, I present illustrations of the terminal abdominal sternites of the male showing lobe on posterior margin of eighth sternite, fig. 103, the terminal abdominal sternites of the female showing shape of subgenital plate (eighth sternite), fig. 103. and the color pattern of the dorsum of the head and pronotum, fig. 103. Additional distributional records based up- on Illinois Natural History Survev collections and material submitted for identification are as follows. Connecticut. — Waterbury, Bristol Park: March 24, 1937, H. H. Ross, 8 nymphs. New Hampshire. — Nelson, Silver Lake Stream: Aug., 1930, C. N. Hardy, 2 nymphs. New York.—Rinowood: April 30, 1937, Lot 770, 1 nymph. North Carolina. — Blowing Rock, near Grandfather Mountain, west of town: March 23, 1940, Prison, Mohr cS; Hawkins, 7 nymphs. Newfound Gap: 3,560 feet altitude. May 28, Nymphal Maxilla (f Terminal Abdominal Sternites 9 Terminal Abdominal «. 125.— AUoperla novasiotiana. 1940, T. H. Prison & T. H. Prison, Jr., 5 <5 , 32$. In fig. 126 are illustrations of these specimens as follows: dorsum of male abdomen, lateral view of male terminal SSUBCENITAL PLATE gin produced backwards over ninth ster- nite, its tip somewhat truncate. Allotype, female.—Essex County, Artist's Brook, N. Y.: June 23, 1940, H. D. Dietrich. New records for this species are as follows. New York.—Cold Brook: June 30, 1940, H. Dietrich, 1$. Essex County, Artist's Brook: June 23, 1940, H. Dietrich, 3$, 10$. Mount Marcy: June 29, 1940, H. Dietrich, 16, 1$. Pennsylvania.—Swiftwater, Monroe Coun- ty: 1928, F. R. Nevin, Lot 258, 2$. AUoperla fidelis Banks AUoperla fidelis Banks (1920, p. 323). Orig- inal description, $ . It seems desirable to record here a series of adults with brachypterous wings, both males and females, which are apparently of the species fidelis. The only differences noted between the typical fidelis and these specimens are the smaller average size, the short wings in both sexes, a slight differ- ence in shape of the indention on the pos- terior margin of the subgenital plate in the female, and the somewhat narrower supra-anal process of the male. These are the first specimens of AUoperla I have ever seen which were brachypterous, but Ricker (1939) has recorded brachypterous forms of the same species from small creeks at high elevations in British Columbia. It is of interest to note that both sexes in these specimens are short winged, whereas in many species of stoneflies this condition occurs or is reported to occur only in the inales. The specimens have the following data. Wyoming.—Dunraven Pass, Mount Wash- burn, Yellowstone National Park: Aug. 2, (J Abdominal TERCITES (J Abdominal segments Fig. 126.—AUoperla fidelis. abdominal segments, supra-anal process of male, subgenital plate of female, and head and pronotum. AUoperla pallidula (Banks) Chloroperla pallidula Banks (1904, p. 99). Original description, $. AUoperla diibia Prison (1935^, p. 338). Original description, $, $. New synonymy. In 1935, I described diibia as a new species closely related to pallidula and differing from it in having a median, longitudinal, dorsal, dark stripe on the abdomen. Although Needham & Claas- sen (1925) had treated pallidula as a species with this dark stripe, I had dis- regarded their concept of this species be- cause of information from Dr. Nathan Banks that pallidula did not have such a stripe, and there was no indication in the original description of such a stripe on the typic specimen. Septi 1942 Prison: North American' Pi.ecoptera 347 A recent study of the typic female of pallidiila in the collection of the Museum of Comparative Zoology has revealed that, although faded and barely distinguishable, the type of pallidu la does have the dorsal, longitudinal, dark stripe on the abdomen, as Needham & Claassen (1925) stated. Although females of Alloperla are not as satisfactory as males for purposes of spe- cific recognition, I have come to the con- clusion that pallidu la and dubia are the same species and therefore the name dubia should fall in synonymy upon the basis of priority. This paper is also the proper place to correct another statement made by me in my \9Z5b paper involving dubia. At that time, I recorded that three specimens of the "Aug., Estes Park, Colo." material recorded by Needham & Claassen (1925) were without a dark dorsal stripe on the abdomen "and hence agree with the true pallidula Banks," as I then accepted it. A restudy of these specimens reveals that this stripe was originally present but is now barely distinguishable because of fad- ing or bleaching in preservative. Recent- ly, Hoppe (1938) recorded both pallidula and dubia from Washington, but a check of her material named as these two species reveals that only one species — dubia—is involved. In other words, there is now no evidence that a western species exists which is structurally like pallidula but that differs in lacking the dark dorsal ab- dominal stripe. Alloperla diversa Frison Alloperla diversa Frison {\9lSb, p. 333). Original description, 6, 2. Alloperla nimbilis Hoppe (1938, p. 155). Original description, $ . New synonymy. A study of the male type of nimbilis, through the courtesy of Professor Trevor Kincaid of the University of Washington, has revealed that it is practically identical with the male type of diversa, described from Oregon. The supra-anal process may differ slightly, but certainly no differences exist to warrant separate specific recogni- tion, in the absence of other characters. Hoppe did not record diversa from Wash- ington, and no mention is made in the original description of /limbilis of differ- ences from or similarities to diversa. Alloperla chloris Frison Alloperla chloris Frison (1934, p. 27). Orig- inal description, ^ , 5 . Chloroperla milnei Ricker (1935, p. 198). Original description, $ , $ . New synonymy. A restudy of a paratypic specimen of miliiei in the Illinois Natural History Survey collection and the cleared terminal abdominal segments of another paratypic specimen sent to me by Dr. W. E. Ricker on loan from the Royal Ontario Museum of Zoology, Toronto. Canada, has re- vealed that milnei is a synonym of chloris. Dr. Ricker states in a letter to me that he concurs with my opinion regarding this synonymy. LITERATURE C I T ED Alexander, (]. I'. 1936. A new species of Periodfs from the White Mountains, New Hampshire. Brooklyn Knt. Soc. Hul. 31 :24-7. Ranks, Nathan 1895. New neuropteroid insects. Am. Ent. Soc. Trans. 22:313-6. 18'^8. Descriptions of new North American neuropteroid insects. Am. Ent. Soc. Trans. 25:199-201. 19(10. New genera and species of Nearctic neuropteroid insects. Am. Ent. Soc. Trans. 26:239-59. June. 1904. Neuropteroid insects from New Mex- ico. Am. Ent. Soc. Trans. 30:97-110. 1905. Descriptions of new species of neu- ropterous insects from the Black Mountains, N. C. Am. Mus. Nat. Hist. Bui. 21:215-8. 1906rt. Descriptions of new Nearctic neurop- teroid insects. Am. Ent. Soc. Trans. 32:1-51. Pis. 1-5. Nov.-Dec, 1905. 1906/^. On the perlid genus Chloroperla. Ent. News 17(5) :174-5. May. 1906f. New species of Periidae. Can. Ent. 38:335-8. 1907. A list of Periidae from British Co- lumbia and Alberta. Can. Ent. 39: 325-30. 1908a. Neuropteroid insects—notes and de- scriptions. Am. Ent. Soc. Trans. 34: 255-67. 1908/;. Trichoptera, and allied insects, from Newfoundland. Psyche 15:66. 1911. Descriptions of new species of North American neuropteroid insects. Am. Ent. Soc. Trans. 37:335-7. 1914. New neuropteroid insects, native and exotic. Acad. Nat. Sci. Phila. Proc. 66:608-11. 1918. New neuropteroid insects. Mus. Comp. Zool. Bui. 62(l):3-22. 2 pis. March. 1920. New neuropteroid insects. Mus. Comp. Zool. Bui. 64:314-25. 1938. .New native neuropteroid insects. Psyche 45:73-5. Burmeister, H. 1839. Plecoptera. Handbuch der Entomol- ogie, band II, part 2, pp. 863-81. T. C. F. Enslin, Berlin. (^laassen, Peter W. 1923. New species of North American Plecoptera. Can. Ent. 55( 12) :257-63, 281-92. 1 pi. Dec. 1924. New species of North American Cap- niidae (Plecoptera). Can. Ent. 56 (2):43-8. Feb. 1928. Additions and corrections to the monograph on the Plecoptera of North America. Ent. Soc. Am. Ann. 21(4):667-8. Dec. 1931. Plecoptera nymphs of America (north of Mexico). Thomas Say Found. Pub. 3. 199 pp., 35 pis. 1937rt. New species of stoneflies (Plecop- tera). Can. Ent. 69:79-82. 1 pi. April. 1937/;. New species of stoneflies (Plecop- tera). Kans. Ent. Soc. Jour. 10(2): 42-51. 1 pi. April. 1940. A catalogue of the Plecoptera of the world. Cornell Univ. Ag. Exp. Sta. Memoir 232:1-235. June. Clark, Robert L. 1934. The external morphology of Acro- neuria rvnluta Klapalek (Periidae, Plecoptera). Ohio Jour. Sci. 34(2): 121-8. 17 tigs. March. Despax, R. 1936. Contribution a Tetude du genre Chlo- roperla [Pictet] [Isoperla Banks) [Plecoptera]. Toulouse Societe d'His- toire Naturelle Bulletin 69(3) :337-98. Fitch, Asa 1847. Winter insects of eastern New York. Am. Jour. Ag. Sci. 5(13) :274-84. May. Prison, Theodore H. 1929. Fall and winter stoneflies, or Plecop- tera, of Illinois. 111. Nat. Hist. Surv. Bui. 18(2) :340-409. 77 figs. May. 1934. Four new species of stoneflies from North America (Plecoptera). Can. Ent. 66(2) :25-30. 16 figs. Feb. 1935rt. The stoneflies, or Plecoptera, of Illi- nois. III. Nat. Hist. Surv. Bui. 20(4) : 281-471. Frontis. + 344 figs., bibliog., index. 193 5/y. New North American species of the genus Alloperla. Am. Ent. Soc. Trans. 61:331-44. 1936. Some new species of stoneflies from Oregon (Plecoptera). Ent. Soc. Am. Ann. 29(2) :256-65. June. 1937. Studies of Nearctic aquatic insects: Descriptions of Plecoptera. 111. Nat. Hist. Surv. Bui. 21(3):78-99. Figs. 65-86. Sept. 1942. Descriptions, records and systematic notes concerning western North American stoneflies (Plecoptera). Pan-Pacific Ent. 18(1):9-16; (2) :61- 73. 19 figs. Jan., April. Carman, H. 1912. A preliminary study of Kentucky localities in which pellagra is prev- alent. Ky. Ag. Exp. Sta. Bui. 159: 58-60. Figs. 47, 48. Jan. [348] September, 1942 Prison: North American Plecoptera 349 Gerstaecker, A. 1873. ITeber Pteionarcys Newm. und eine zweite, in Imago-Stadium mit Tra- cheenkiemen versehene Perlarien- Gattuiig. Festschrift ziir Feier des lOO-jiihrigen Bestehens der Gesell- schaft Naturforschender Freunde zu Berlin, pp. 39-74. Hagen, Hermann 1861. Synopsis of the Neuroptera of North America. Smithsn. Inst. Misc. Col- lect. XX -|- 347 pp. Washington, D. C. July. 1873. Perlina. Boston Soc. Nat. Hist. Proc. 15:281-90. 1874. Family Perlina. U. S. Geol. and Geog. Surv. Terr. Ann. Rep. 1873: 573-7. Hanson, John F. 1938. Studies on the Plecoptera of North America I. Brooklyn Ent. Soc. Bui. 33:79-83. 1941. Studies of the Plecoptera of North America II. Brooklyn Ent. Soc. Bui. 36:57-66. 15 figs. Hoppe, Gertrude N. 1938. Plecoptera of Washington. Wash. [State] Univ. Pubs. Biol. 4(2) :139- 74. 25 figs. Hynes, H. B. N. 1941. The taxonomy and ecology of the nymphs of British Plecoptera with notes on the adults and eggs. Roy. Ent. Soc. London Trans. 91(10) :459- 557. 24 figs., 1 map. Dec. Kimmins, D. E. 1936. Synonymic notes on the genera Chloroperla, Isopteryx and Isoperla (Plecoptera). Soc. Brit. Ent. Jour. 2:121-4. March. Klapalek, Franz 1902. Zur Kenntniss der Neuropteroiden von Ungarn, Bosnien und Herzego- vina. Termeszetrajzi Fiizetek, Buda- pest, 25:178-80. 1907. Beitrag zur Kenntnis der Gattung Pteronarcys Newman. Bulletin Inter- national, Academie des Sciences de I'Empereur Francois Joseph I, 12: 150-62. 10 figs. 1909. Revision der Gattung Acroneuria Pict. Bulletin International, Acad- emie des Sciences de I'Empereur Frangois Joseph I, 14:234-47. 10 figs. Nov. 1912. Collections zoologiques du Baron Edm. de Selys Longchamps, Cata- logue systematique et descriptif. Fasc. IV (Plecopteres). I. Fam. Perlodi- dae. 66 pp., 58 figs. June 25. 1916. Subfamilia Acroneuriinae Kip. Ceske Spolecnosti Entomologecke Casopis 13:45-84. 1917. Ceske Spolecnosti Entomologecke Ca- sopis 14:40-57. 1923rt. Collections zoologiques du Baron Edm. de Selys Longchamps, Cata- logue systematique et descriptif. Fisc. IV- (Plecopteres). II. Fam. Perli- dae, subfam. Perlinae, Neoperlinae. 193 pp., 85 + 61 figs. March 1. 1923//. Plecopteres nouveaux. Soc. Ent. Bel- gique Ann. 63:21-9. Neave, Ferris 1929. Reports of the Jasper Park Lakes Investigations 1925-26. II. Plecop- tera. Contributions to Can. Biol, and Fish. 4(13) :159-68. 21 figs. 1933. Some new stoneflies from western Canada. Can. Ent. 65(10) :235-8. Figs. 1-5. Oct. 1934. Stoneflies from the Purcell Range, B. C. Can. Ent. 66(1) :l-6. 1 fig. Needham, James G. 1905. New genera and species of Perlidae. Biol. Soc. Wash. Proc. 18:107-10. March 31. 1933. A stonefly nymph with paired lateral abdominal appendages. Jour. Ent. and Zool. 25:17-9. 1 fig. Needham, J. H., and P. W. Claassen 1922. The North American species of the genus Acroneuria (Order Plecop- tera). Can. Ent. 54(11) :249-55. Nov. 1925. A monograph of the Plecoptera or stoneflies of America north of Mexico. Thomas Say Found. Ent. Soc. Am. 2. 397 pp., 50 pis., 29 figs. Newman, Edward 1836. Entomological notes. Ent. Mag. 3 499-501. 1838rt. Entomological notes. Ent. Mag. 5 175-8. 1838Z'. Entomological notes. Ent. Mag. 5 483-500. 1839. On the synonymy of the Perlites, to- gether with brief characters of the old, and of a few new, species. Mag. Nat. Hist. n.s. (ser. 2) 3:32-7, 84-90. Newport, George 1851. On the anatomy and aflinities of Pteronarcys regalis Newm.: with a postscript, containing descriptions of some American Perlidae, together with notes on their habits. Linn. Soc. Lond. Trans. 20(3) :447-52. PI. 21. Pictet, F. J. 1841. Histoire naturelle generale et partic- uliere des insectes Nevropteres. Pre- miere Monographie: Famille des Perlides. 423 pp., 53 colored pis. J. Kessman, Geneve. Provancher, Abbe L. 1876. Petite faune entomologique du Can- ada, Fam. II, Perlides, Gen. 1, Ptero- narcys. Nat. Can. 8:188-91. June. Rambur, M. P. 1842. Histoire naturelle des insectes—Nev- ropteres. xvii+ 534 pp., 12 colored pis. Roret, Paris. .?50 Illinois Natlr.m. History Survey Bulletin I ol. 22. Art. 2 Kicker. William E. 193Srt. Descriptions of three new Canadian perli.is. Can. Knt. 67(9) :197-201. Sept. 1935/'. New Canadian perlids (part II). Can. Knt. 67( 12) :256-64. 1 pi. Dec. 1938. Notes on specimens of American Pie- coptera in Kuropean collections. Roy. Can. Inst. Trans. 22:129-56. 38 figs. Oct. 1939. A preliminary list of stoneflies (Ple- coptera) from the vicinity of Cultus Lake, British Columbia. Ent. Soc. Brit. Columbia Proc. 35:19-23. Say, Thomas 1823. Descriptions of insects belonging to the order Neuroptera Lin., Latr. Col- lected by the expedition authorized by J. C. Calhoun, Secretary of War, under the command of Major S. H. Long. West. Quart. Rep. 2:160-5. April-May-June. Smith, L. W. 1917. Studies of North American Plecop- tera (Pteronarcinae and Perlodini). Am. Ent. Soc. Trans. 63:433-89. Dec. 28. Pis. XXIX-XXXIV, figs. A-E. Stephens, J. F. 1835. Illustrations of British entomology, 6: Mandibulata, 134-45. PI. XXXI. Baldwin & Cradock, London. Walker, F. 1852. Catalogue of the specimens of neu- ropterous insects in the collection of the British Museum. Part I, pp. 1- 192. London, by order of the Trus- tees. Walsh, B. D. 1862. List of the Pseudoneuroptera of Illi- nois contained in the cabinet of the writer, with descriptions of over 40 new species, and notes on their struc- tural affinities. Acad. Nat. Sci. Phila. Proc, Sept., 362-7. 1863. Perlina. Notes by Benj. D. Walsh. Ent. Soc. Phila. Proc. 2(3):186-8. Oct. Westwood, J. O. 1840. Synopsis of the genera of British insects—Perlidae Leach. P. 47. Wu, Chenfu F. 1934. A homonym of a Piecopterous genus. Ent. Soc. Am. Ann. 27(2) :256. June. INDEX Bold face type indicates a principal reference. Both principal and subsidiary references may occur on the same page. A species name appearing in the heading or bibliographic subheading of a description is indexed for the page on ivliich it first occurs and not again in that description. Acroneuria, 237, 240, 241 abnormis, 241 arenosa, 272, 275 areta, 240 arida, 241, 272, 273, 274, 277, 278 brevicauda, 277 californica, 284 carolinensis, 281, 283 clara, 275 cuestae, 281 depressa, 284, 285, 302 depressa ( ?), 286 evoluta, 241, 272, 273, 274, 277 filicis, 275 georgiana, 280 internata, 241 lycorias, 281, 283 mela, 241, 274, 277 pacifica, 284 pennsylvanica, 275, 276 perbranchiata, 281, 283 perplexa, 241, 277 prolonga, 272, 273 ruralis, 241 sabulosa, 285, 302 sp. a, 241, 274 theodora, 284 valida, 273, 274 xanthenes, 277 abnormis, Acroneuria, 241 Adelungia arctica, 286 caudata, 286 aestivalis, Diploperla, 302 aestivalis, Perla, 302 alameda, Diploperla, 302 alameda, Perla, 302 alex, Taeniopteryx (Oemopteryx), 251 Allocapnia, 237, 241, 262, 265, 342 curiosa, 268, 269, 270 forbesi, 241, 269 cornuta, 241 granulata, 241 illinoensis, 241, 269 incisura, 266 mystica, 241, 262 pygmaea, 241, 265, 269 recta, 241 rickeri, 241, 267, 269 sp., 266 torontonensis, 265 virginiana, 269 vivipara, 241, 265 AUoperla, 237, 242, 337, 338, 339, 340, 344 banksi, 242, 339, 343 caudata, 242, 339, 342 chloris, 347 concolor, 345 cydippe, 338 diversa, 347 dubia, 346 fidelis, 346 lodgei, 344 nanina, 343, 344 neglecta, 345 nimbilis, 347 novascotiana, 345 pallidula, 346 americana, Perlodes, 288 annecta, Clioperla, 329 arctica, Adelungia, 286 arctica, Claassenia, 285, 286 arcuata, Peltoperla, 246, 247 Arcynopteryx, 287 aurea, 287, 288 lineata, 287, 288 minor, 287 vagans, 287, 288 arenosa, Acroneuria, 272, 275 areta, Acroneuria, 240 arida, Acroneuria, 241, 272, 273, 274, 277, 278 arida, Perla, 272 arina, Diploperla, 309 Atoperla, 237, 241 ephyre, 241 aurea, Arcynopteryx, 287, 288 aurea, Perlodes, 288 banksi, AUoperla, 242, 339, 343 Banksiella kansensis, 278 barbara, Oroperla, 287 bicaudata, Dictyopterygella, 301 bicaudata, Phryganea, 301 bilineata, Isoperla, 242, 311, 315, 316, 320, 321, 323, 325, 332, 338 biloba, Pteronarcys, 245 bilobata, Diploperla, 239, 302, 307, 311 bilobata, Perla, 302 bipunctata, Perla, 301 Brachyptera, 237, 238, 241, 248, 250 contorta, 253 fasciata, 241, 248, 250, 254, 256 glacialis, 251 limata, 255 nigripennis, 256 oregonensis, 251 pacifica, 251, 256 rossi, 254 trifasciata, 248 vanduzee, 253 (Brachyptera) glacialis, Nemoura, 251 bradleyi, Protarcys, 287, 289 brevicauda, Acroneuria, 277 brevis, Hastaperla, 242, 338, 339, 340 brevis, Chloroperla, 338, 340 brevis, Peltoperla, 245, 246 bulbosa, Diploperla, 307 burksi, Isoperla, 242, 332 californica, Acroneuria, 284 californica, Nemoura, 261 capitata, Neophasganophora, 241, 302 capitata, Perla, 302 Capnella pygmaea, 265 vivipara, 265 [351] 352 IiiiNdis NvriRAi HIs^()R^ Slrvi.v Hli,i.i:tin lol. 22. An. 2 Capnia. 237. 241. 262 minima ( ?), 265 opis. 241. 262, 264. 266 sp.. 262 vfrnalis ( ?). 240. 241, 262, 264 Capnii.lac. 237, 238. 239. 241, 262 Capnura, 237 Carolina, Nemocapnia, 241, 262 carolineiisis, Acroneuria, 281, 283 carolinensis, Peria, 281 cascadcnsis, Isoperla, 337 caudata, Adelungia. 286 caudata. Alloperia, 242, 339, 342 chloris, Alloperia, 347 Chioropcrla, 237, 337, 338, 339 brevis, 338, 340 cydippc, 337, 338, 339, 340 holochlora, 311 lutea, 337 milnei, 347 montana, 330, 331 nana, 344 orpha, 338, 339, 340 opis, 264 pallidula, 346 terna, 339 transmarina, 316 tripunctata, 337, 338, 340 Chloroperlidae, 237, 238, 239, 240, 242. 337 chrvsannula, Isoperla, 337 claasseni, Leuctra, 241. 256, 258, 259 claasseni, Paraleuctra, 256, 257 Claassenia, 237, 238, 286, 301 arctica, 285, 286 languida, 286, 301, 302 clara. Acroneuria, 275 clio, Clioperla, 336 clio, Isoperla, 242, 330, 334, 336 Clioperla annecta, 329 clio, 336 clymene, Neoperia, 241 colubrinus, Isogenus, 290 comstocki, Pteronarcys, 245 concolor, Alloperia, 345 confusa, Isoperla, 242, 330, 331 conspicua, Isoperla, 242 contorta, Brachyptera, 253 contorta, Taeniopteryx, 253 Cornelia, Peltoperla, 247 cornuta, Allocapnia forbesi, 241 crosbyi, Hydroperla, 241, 293, 295, 296, 302 crosbyi, Perla, 302 cuestae, Acroneuria, 281 curiosa, Allocapnia, 268 cydippe, Alloperia, 338 cydippe, Chloroperia, 337, 338, 339, 340 cydippe, Hastaperia, 242, 339 cydippe, Isopertyx, 340 decepta, Isoperla, 242, 323, 324 decepta, Leuctra, 241, 256, 257, 258, 259 depressa, Acroneuria, 284, 285, 302 depressa (?), Acroneuria, 286 dicala, Isoperla, 240, 241, 321, 324 Dictyogenus ( ?) phaleratus, 302 Dictyopterygella, 237, 238, 239, 240 bicaudata, 301 knowltoni, 299, 305 Dictyopteryx irregularis, 287, 290 signata, 287. 290 Diploperla, 237. 238, 239, 240. 301. 302 aestivalis, 302 alameda, 302 arina, 309 bilobata, 239. 302, 307. 311 bulbosa, 307 duplicata, 239, 302, 311 errata, 302 expansa, 302, 305, 307 fugitans, 302 hastata, 300. 302, 309, 325 innubila, 302 luctuosa, 239, 302 misnoma, 302 modesta, 302, 303, 307 nona. 302 phalerata, 302 pilata, 305 ramosa, 302 sorpta, 302 tinctata, 302 verticalis, 302, 311 diversa, Alloperia, 347 dolobrata, Perlodes, 289 dolobrata, Protarcys, 287, 289 dorata, Hydroperla, 293, 295 dorsata, Pteronarcys, 242, 244 dorsata, Sialis, 242 drymo, Perlinella, 241 dubia, Alloperia, 346 duplicata, Isoperla, 241, 302 duplicata, Perla, 302 duplicata, Diploperla, 239, 302, 311 duplicata, Perla, 302 Eccoptura xanthenes, 277 elongatus, Isogenus, 290, 291 ephyre, Atoperla, 241 errata, Diploperla, 302 errata, Perla, 302 Eucapnopsis, 237, 238 evoluta, Acroneuria, 241, 272, 273, 274. 277 expansa, Diploperla, 302, 305, 307 expansa, Perla, 302, 305 extensa, Isoperla, 315 fasciata, Brachyptera, 241, 248, 250, 254, 256 fasciata, Semblis, 250 fasciata, Strophopteryx, 250 fidelis, Alloperia, 346 filicis, Acroneuria, 275 Filipalpia, 237, 239 flavicornis, Pteronarcys, 242 forbesi, Allocapnia, 241, 269 cornuta, 241 forcipata, Leuctra, 259 frigida, Pteronarcys, 242 frontalis, Isogenus, 290 frontalis, Paraperla, 339 fugitans, Diploperla, 302 fugitans, Perla, 302 fulva, Isoperla, 315, 337 fusca, Isoperla, 317 Carman, Larva No. 1, 273 georgiana, Acroneuria, 280 georgiana, Perla, 280 glacialis, Brachyptera, 251 glacialis, Xemoura (Brachyptera), 251 glacialis, Taeniopteryx, 251 granulata, Allocapnia, 241 hartl, Hydroperla, 241, 293, 295, 296 September. 1942 Frison : North American Plecoptera 353 Hastaperla, 237, 238, 239, 242, 338, 339, 340 brevis, 242, 338, 339, 340 cydippe, 242, 339 oVpha, 338, 340 hastata, Diploperla. 300, 302, 309, 325 hastatus, Isogenus, 302 holochlora, Chloroperla, 311 holochlora, Isoperla, 311 Holognatha, 237 Hydroperla, 237, 239, 240, 241, 287, 292, 300, 301, 302 crosbyi, 241, 293, 295, 296, 302 dorata, 293, 295 hard, 241, 293, 295, 296 nalata, 293, 295, 296 olivacea, 296 parallela, 293, 295, 296, 298 subvarians, 292, 295, 296. 302 varians, 241, 293, 295, 296, 302 ignota, Perlodes, 288 illinoensis, Allocapnia, 241, 269 immarginata, Perla, 302 immarginata, Togoperla, 302 incesta, Perla, 290 incisura, Allocapnia, 266 innubila, Diploperla, 302 innubila, Perla, 302 insignis, Kollaria, 242 insipida, Isoperla, 321 internata, Acroneuria, 241 irregularis, Dictyopteryx, 287, 290 Isocapnia, 237 Isogenus, 237, 239, 240, 287, 291, 301 colubrinus, 290 elongatus, 290, 291 frontalis, 290 hastatus, 302 Isoperla, 235, 237, 238, 240, 242, 302, 311, 337, 338, 339 bilineata, 242, 311, 315, 316, 320, 321, 323, 325, 332, 338 burksi, 242, 332 cascadensis, 337 chrysannula, 337 clio, 242, 330, 334, 336 confusa, 242, 330, 331 conspicua, 242 decepta, 242, 323. 324 dicala, 240, 241, 321, 324 duplicata, 241, 302 extensa, 315 fulva, 315, 337 fusca, 317 holochlora, 311 insipida, 321 lata, 334 longiseta, 242, 318. 321 marlynia, frontispiece, 242, 330, 334, 336 minuta, 242, 323, 344 mohri, 242 montana, 331 mormona, 318, 319, 320. 321 namata, 240, 327 orata, 323 patricia, 312, 313 pinta, 329, 337 richardsoni, 242 signata, 328, 329 similis, 325 slossonae, 329 tokula, 337 transmarina, 316 trictura, 336 truncata, 324, 325 ventraiis, 316, 334 Isoperlidae, 237, 239, 240, 242, 311 Isopteryx, 337, 338 cydippe, 340 kansensis, Banksiella, 278 kansensis, Perla, 302 kansensis, Togoperla, 241, 277, 302 Kathroperla, 237, 239, 338, 339 kincaidi, Taeniopteryx, 251 knowltoni, Dictyopterygeiia, 299, 305 Kollaria insignis, 242 languida, Claassenia, 286, 301, 302 languida, Perla, 286, 301, 302 lata, Isoperla, 334 Leuctra, 237, 241, 256, 260, 342 claasseni, 241, 256, 258, 259 decepta, 241, 256, 257, 258, 259 forcipata, 259 occidentalis, 259, 260 projecta, 260 purcellana, 259 sara, 241, 259 tenuis, 241, 256, 257, 258, 261 Leuctridae, 237, 238, 239, 241, 256 iimata, Brachyptera. 255 lineata, Arcynopteryx, 287, 288 lita, Taeniopteryx, 241, 249 lobata, Nemoura, 261 lodgei, AUoperla, 344 longiseta, Isoperla, 242, 318, 321 luctuosa, Diploperla, 239, 302 luctuosa, Perla, 302 lurida, Perla, 282 lutea, Chloroperla, 337 lycorias, Acroneuria, 281, 283 lycorias, Perla, 283 margarita, Perlodes, 288 marlynia, Isoperla, frontispiece, 242, 330, 334, 336 maura, Nemoura, 248 maura, Taeniopteryx, 241, 248, 253 maxima, Perla, 301 media, Perla, 302 media, Togoperla, 241, 302 Megaleuctra, 237 Megarcys, 287 mela, Acroneuria, 241, 274, 277 milnei, Chloroperla, 347 minima (?), Capnia, 265 minor, Arcynopteryx, 287 minor, Perlodes, 287 minuta, Isoperla, 242, 323, 344 misnoma, Diploperla, 302 misnoma, Perla, 302 modesta, Diploperla, 302, 303, 307 modesta, Perla, 302, 303 mohri, Isoperla, 242 montana, Chloroperla, 330, 331 montana, Isoperla, 331 mormona, Isoperla, 318, 319, 320, 321 mystica, Allocapnia, 241, 262 nalata, Hydroperla, 293, 295, 296 namata, Isoperla, 240, 327 nana, Chloroperla, 344 nanina, AUoperla, 343, 344 354 Illinois Natural History Survhv Uullktix J'ol. 22, Art. 2 nrbulosa, 'racnioptcryx, 248 iicglecta, Alloperia, 345 Ncmocapiiia, 237, 238, 241, 262 Carolina, 241, 262 Ncmoura, 237. 238, 241, 260. 342 (Brachyptera) glacialis, 251 californica, 261 lubata, 261 maiira, 248 nivalis, 248 tenuis, 258 trispinosa, 241, 260. 261 venosa, 241, 260, 261 Nemouridac, 237. 238. 239, 241, 260 Neoperla, 237. 241 clyineiie. 241 Ncophasgaiiophora, 237, 240. 241, 302 capitata, 241, 302 Nephelopteryx, 248 Nephopteryx. 238 iiiKripennis, Brachyptera, 256 iiimbilis, Alloperia, 347 nivalis. Nemoura, 248 nivalis, Taeniopteryx, 241, 248, 250. 253 ni\icola. Perla, 265 nobilis, Pteronarcys, 241, 242, 244 nona. Diploperia, 302 nona, Perla, 302 novascotiana, Alloperia, 345 Obipteryx, 238 obscura, Perla, 302 occicientalis, Leuctra, 259, 260 Oemopteryx, 238. 250 (Oemopteryx) alex, Taeniopteryx, 251 olivacea, Hydroperla, 296 olivacea, Perla, 296 opis, Capnia, 241, 262, 264, 266 opis, Chloroperia, 264 orata, Isoperla, 323 oregonensis, Brachyptera, 251 oregonensis. Taeniopteryx, 251 Oroperia, 237, 238 barbara, 287 orpha, Chloroperia, 339, 340 orpha, Hastaperia, 338, 340 pacifica, Acroneiiria, 284 pacifica, Brachyptera, 251. 256 pacifica, Taeniopteryx, 251 pallida. Taeniopteryx, 252 pallidula, Alloperia, 346 pallidula, Chloroperia, 346 Paraleuctra, 256, 257, 260 claasseni, 256, 257 projecta, 260 parallela, Hydroperla, 293, 295, 296, 298 Paraperia, 237, 338. 339 frontalis. 339 parvula, Taeniopteryx, 241, 249, 250 patricia, Isoperla, 312, 313 Peltoperia, 237 arcuata, 246, 247 brevis. 245, 246 Cornelia, 247 zipha, 247 Peltoperlidae. 237, 238, 239, 245 pennsylvanica, Acroneuria, 275 perbranchiata. Acroneuria. 281, 283 Perla, 238. 300, 301, 302 aestivalis, 302 alameda, 302 arida, 272 bilobata, 302 bipiinctata, 301 caroliiiensis. 281 capitata. 302 crosbyi, 302 duplicata, 302 errata, 302 expansa, 302, 305 fugitans, 302 georgiana, 280 immarginata, 302 incesta, 290 iniuibila, 302 kansensis, 302 languida, 286, 301. 302 luctuosa, 302 lurida, 282 lycorias, 283 maxima, 301 media, 302 misnoma, 302 modesta, 302, 303 nivicola, 265 nona, 302 obscura, 302 olivacea, 296 placida, 271 postica, 292, 293, 302 ramosa, 302 sabulosa, 285, 302 similis, 325 slossonae, 329 sorpta, 302 subvarians, 292 tincta, 302 tinctata, 302 titusi, 290 trictura, 336 valida, 272 varians, 302 venosa, 302 verticalls, 302 xanthenes, 277 Perlesta, 237, 241 placida, 241, 271 Perlidae, 237, 238, 239, 241, 271, 301, 311 Perlinella, 237, 241 drymo, 241 Perlinodes, 287 Perlodes, 237, 238, 239, 240, 287, 292, 300, 301 americana, 288 aurea, 288 dolobrata, 289 ignota, 288 margarita, 288 minor, 287 signata, 290 slossonae, 287, 289 tibialis, 287, 289 vosemite, 287, 290 Perlodidae, 237, 238, 239, 240, 241, 287, 300, 301, 311 Perlomyia, 237 perplexa, Acroneuria, 241, 277 phalerata, Diploperia, 302 phaleratus, Dictyogenus (?), 302 Phryganea bicaudata, 301 pictetii, Pteronarcys, 241, 242, 244 pilata, Diploperia, 305 pinta. Isoperla, 329, 337 placida, Perla, 271 September, 1942 Frison : North American Plecoi^tera 355 placida, Perlesta, 241, 271 Plecoptera, List of the Illinois, 241 Plecoptera, Revised classification, 237 Plecoptera, Revised key to families, 238 postica, Perla, 292, 293, 302 projecta, Leuctra, 260 projecta, Paraleuctra, 260 prolonga, Acroneuria, 272, 273 Protarcys, 287, 289 bradleyi, 287, 289 dolobrata, 287, 289 proteus, Pteronarcys, 242, 244, 245 Pteronarcella, 237 Pteronarcidae, 237, 238, 239, 241, 242 Pteronarcvs, 237, 240, 241, 242 biloba, 245 comstocki, 245 dorsata, 242, 244 flavicornis, 242 frigid a, 242 nobilis, 241, 242, 244 pictetii, 241, 242, 244 proteus, 242, 244, 245 rectus, 242 regalis, 242, 244 shelfordi, 242 species, 245 purcellana, Leuctra, 259 pygmaea, Allocapnia, 241, 265, 269 pygmaea, Capnella, 265 pygmaea, Semblis, 265 ramosa, Diploperla, 302 ramosa, Perla, 302 raynoria, Taeniopteryx, 251 recta, Allocapnia, 241 rectus, Pteronarcys, 242 regalis, Pteronarcys, 242, 244 Rhabdiopteryx, 238, 250 richardsoni, Isoperla, 242 rickeri, Allocapnia, 241, 267, 269 rossi, Brachyptera, 254 ruralis, Acroneuria, 241 sabulosa, Acroneuria, 285, 302 sabulosa, Perla, 285, 302 sara, Leuctra, 241, 259 Semblis fasciata, 250 pygmaea, 265 Setipalpia, 237 shelfordi, Pteronarcys, 242 Sialis dorsata, 242 signata, Dictyopteryx, 287, 290 signata, Isoperla, 328, 329 signata, Perlodes, 290 similis, Isoperla, 325 similis, Perla, 325 slossonae, Isoperla, 329 slossonae, Perla, 329 slossonae, Perlodes, 287, 289 sorpta, Diploperla, 302 sorpta, Perla, 302 Strophopteryx, 238, 248, 250 fasciata, 250 Subulipalpia, 237, 239 subvarians, Hydroperla, 292, 295, 296, 302 subvarians, Perla, 292 Systellognatha, 237 Taeniopterygidae, 237, 238, 239, 241, 247, 250 Taeniopteryx, 237, 241, 248, 250 contorta, 253 glacialis, 251 kincaidi, 251 lita, 241, 249 maura, 241, 248, 253 nebulosa, 248 nivalis, 241, 248, 250, 253 (Oemopteryx) alex, 251 oregonensis, 251 pacifica, 251 pallida, 252 parvula, 241, 249, 250 raynoria, 251 vanduzee, 253 tenuis, Leuctra, 241, 256, 257, 258, 261 tenuis, Nemoura, 258 terna, Chloroperla, 339 theodora, Acroneuria, 284 tibialis, Perlodes, 287, 289 tincta, Perla, 302 tinctata, Diploperla, 302 tinctata, Perla, 302 titusi, Perla, 290 Togoperla, 237, 241, 302 immarginata, 302 kansensis, 241, 277, 302 media, 241, 302 sp. a, 241 tokula, Isoperla, 337 torontonensis, Allocapnia, 265 transmarina, Chloroperla, 316 transmarina, Isoperla, 316 trictura, Isoperla, 336 trictura, Perla, 336 trifasciata, Brachyptera, 248 tripunctata, Chloroperla, 337, 338, 340 trispinosa, Nemoura, 241, 260, 261 truncata, Isoperla, 324, 325 vagans, Arcynopteryx, 287, 288 valida, Acroneuria, 273, 274 valida, Perla, 272 vanduzee, Brachyptera, 253 vanduzee, Taeniopteryx, 253 varians, Hydroperla, 241, 293, 295, 296, 302 varians, Perla, 302 venosa, Nemoura, 241, 260, 261 venosa, Perla, 302 ventralis, Isoperla, 316, 334 vernalis (?), Capnia, 240, 241, 262, 264 verticalis, Diploperla, 302, 311 verticalis, Perla, 302 virginiana, Allocapnia, 269 vivipara, Allocapnia, 241, 265 vivipara, Capnella, 265 xanthenes, Acroneuria, 277 xanthenes, Eccoptura, 277 xanthenes, Perla, 277 yosemite, Perlodes, 287, 290 zipha, Peltoperia, 247 Recent Publications of the Illinois Natural History Survey A.—ILLINOIS NATURAL HISTORY SURVEY BULLETIN. Volume 21, Article 3.—Studies of Nearctic Aquatic Insects. By H. H. Ross and T. H. Prison, September, 1937. 52 pp., frontis. -f 86 figs., bibliog. 50 cents. Volume 21, Article 4.—Descriptions of Nearctic Caddis Flies (Trichoptera), with special reference to the Illinois species. By Herbert H. Ross. March, 1938. 84 pp., frontis. -f 123 figs., foreword, index. $1.00. Volume 21, Article 5.—Preliminary Studies on Parasites of Upland Game Birds and Fur-Bearing Mammals in Illinois. By W. Henry Leigh. August, 1940. 10 pp., frontis. + 2 maps. Volume 21, Article 6.—Preliminary Investigation of Oak Diseases in Illinois. By J. Cedric Carter. June, 1941. 36 pp., frontis. + 51 figs., bibliog. (Boiind witn Article 7.) Volume 21, Article 7.—A Needle Blight of Austrian Pine. By Robert L. Hulbaxy. June, 1941. 6 pp., frontis. + 3 figs., bibliog. (Bound with Article 6.) Volume 21, Article 8.—Duck Food Plants of the Illinois River Valley. By Frank C. Bellrose, Jr. August, 1941. 44 pp., frontis. -f 35 figs., bibliog., appendix. Volume 22, Article 1.—The Plant Bugs, or Miridae, of Illinois. By Harry H. Kni^rht. September, 1941. 234 pp., frontis. + 181 figs., bibliog., index. $1.25. B.—ILLINOIS NATURAL HISTORY SURVEY CIRCULAR. 32.—Pleasure With Plants. By L. R. Tehon. April, 1939. 32 pp., frontis. -f 9 figs. Couteuts: What is boiauiziug? Ways to botanize; Where to botanize; When to botanize ; How to botanize; Studying plants; Equipment for studying plants; The herbarium; Uaefol books ; Maps ; Couclusion. 33.—Controlling Peach Insects in Illinois. By S. C. Chandler and W. P. Flint. Augxut, 1939. 40 pp., frontis. + 32 figs. Contents: Part I. Insects attacking bark and trunk of the peach tree; Part II. Insects attack- ing twigs, foliage and fruit of the peach tree. 34.—Rout the Weeds! Why, When and How. By L. R. Tehon. January, 1940. (Second grinting.) 47 pp., color frontis. + 13 figs, ontents: The importance of weeds; W^eeds as economic factors; Weeds as harborera of Insects; Weeds as harborers of plant diseases; Relation of weeds to public health; Control methods; Thirteen noxious and pernicious weeds of Illinois. 35.—Diseases of Small Grain Crops in Illinois. By G. H. Boewe. September, 1939. 130 Sp., frontis. + 47 figs, ontents: Nature of cereal diseases; Wheat diseases; Oats diseases; Barley diseases; Bye diseases ; Cereal disease control. 36.—Planting and Care of Shade Trees. By J. E. Davis. March, 1941. 23 pp., frontis. + 16 figs. Contents: Introduction; Planning for shade; Planting shade trees; Care of newly planted trees ; Care of older trees ; Some common trees used for shade. 37.—Outwitting Termites in Illinois. By W. E. McCauley and W. P. Flint. August, 1942. (Second printing.) 23 pp., frontis. + 19 figs. Contents: Termites and their habits; Structural control of termites; Control of termites wltb chemicals ; Unified action against termites. 38.—Windbreaks for Illinois Farmsteads. By J. E. Davis. February, 1942. (Second printing.) 24 pp., frontis. + 19 figs. Contents : Introduction ; Planning the windbreak ; Planting the windbreak ; Care of the wind- break; What the windbreak trees are like; Windbreaks and wildlife. 39.—^How to Collect and Preserve Insects. By H. H. Boss. June, 1941. 48 pp., frontis. + 53 figs. Contents : Where to collect ; What to use ; Special collecting equipment ; Sending insecta for identification; How to handle unmounted specimens; How to mount and preserve speci- mens; How to label the specimens; Housing the collection permanently; Identifying the specimens ; Useful books ; How to ship a collection ; Where to buy supplies. 40._Control of Roundheaded Apple Tree Borer. By S. C. Chandler and W. P. Flint April, 1942. 8 pp., 6 figs. C—ILLINOIS NATURAL HISTORY SURVEY MANUAL. 1.—Fieldbook of Illinois Wild Flowers. By the staff. March, 1936. 406 pp., color frontis. + 349 figs., index. $1.50. Contents: Introduction; Key to families; Description of species (660). 2.—Fieldbook of Illinois Land Snails. By Frank Collins Baker. August, 1939. 166 pp., color frontis. + 170 figs., 8 pis. $1.00. Contents: Land snuils, what they are and where they live; Land snails native to Illinois; Land snails introduced from foreign countries; Land snails of uncertain presence in Illinoia; Bibliography; Check list of Illinois species; Index. List of available publicationa, over 300 titles, mailed on requeat. Address orders and correspondence to the Chief ILLINOIS NATURAL HISTORY SURVEY Natural Resources Building. Urbana, Illinois Payment In the form of U. 8. Post Office money order nutde out to State Treasurer of nilnols, Sprlngrfield. XUlnols, mast accompany requests (or those publications on which a priee la eet.