ERRATA. Page 12, lines 16 and 17, for one hundred read three hundred and for one thousand read six hundred. Page 17, line 2, dele first letter in the line. Page 168, line 12, page 177, lines 13 and 14, and page 271, line 10, for Lemna tnsulca read Spirodela polyrMza. Page 209, line 2 of foot-note, after hut insert represents. Page 2;'56, line 7, and page 266, line 19: snoioi n. s. has been shown to be hieroghjijhka, (^. Page 257, insert as line 8 as follows: -ken to the office produced young in ten days. The Page 272, line 13, for P. higuUatus read Pompiliis higuttatus. Page 278, Plate Y., 16, after view insert as follows: a, mentum; 6, labial rudiment; c, maxillary palpi; d, maxilla; e, labrum; /, antenna; g, eye; h, mandible. Page 286, line 11, drop initial the one line. Page 386, line 1, for Comstocki read Comstock. Page 399, line 17, for specimens read specimen. Page 411, line 10, for Michaelson read Michaelsen. Page 441, line 3 from bottom, for 66 read 68. Page 445, line 10 from bottom, for 57 read 5S. Page 466, line 1 from bottom, for Cyima read Oypris. Article V. — A Pi'elhivmary Account of two New Oli- gochmta from Illinois. By Frank Smith. Several species of Oligochseta were collected by the writer during- the past summer at the Biological Station upon the Illinois River, at Havana, founded early in the present year by the University of Illinois, with Prof. S. A. Forbes as Director. Since it will be several months before a full report on the Oligochaeta can be prepared, it seems best to publish this preliminary account of the larger forms collected. In the vicinity of the Station, the Illinois River flows for the greater part of its course between low banks, which are overflowed during the higher stages of water that usually occur in the spring or earJy summer months. They are covered with the usual bottom-land forests and other vegetation of the region. In those portions of the banks that are above water during the greater part of the year, were found many earthworms of a species closely allied to Diplocardia comm^tnis Garman which was de- scribed from Illinois in 1888* and is abundant in the soil of the prairies of the State. Reproductive activity was greatest throughout the month of May, when cocoons were abundant in their burrows. Diplocardia ripaHa nov. sp. This earthworm is quite similar to D. communis in general form, in relative length of somites in different parts of the body, and in the plication and encircling lines of tlie somites. The number of somites is similar, the average of ten specimens being 150, the minimum and maximum numbers respectively 136 and 157. The ordinary length of well-extended specimens is 22 to 25 cm., with a diameter of about .3 cm. *"0n the Anatomy and Histology of a New Earthworm (Diplocardia com- munis, gen. et sp. nov.)." (Bull. III. State Lab. Nat. Hist., Vol. III., Art. IV., p. 47.) Two New OliyocJiceta from Illinois. l;J9 The color is somewhat darker than that of D. commnnis, whicli is flesh-colored. The difference is very pronounced on the dorsal surface of the region anterior to the clitelliini, where the sui-face becomes dark brown, this color being usually retained in alcoholic specimens. Pos- terior to the clitellum the brown dorsal vessel and its lateral branches are very conspicuous through the body wall of the living animal. The clitellum is of a dull copper-color, and extends over somites XIII to XVIII, inclusive. As in D. com- munis, it is ab.sent or but slightly developed upon a narrow median ventral area of those somites. The setae have the same arrangement and distribution as in D. com- munis. The first dorsal jjore is near the groove between X and XI. The number and position of the gizzards, in somites \ and VI, the character of the typhlosole, and other main features of the alimentary tract, are the same in the two species. The nephridiopores are in the vicinity of the outermost setae. The generative systems of the two species are alike in main chatacters, but present specific differences. Two pairs of ciliated rosettes are present in each of the species, occupying the usual position in somites X and XI. An anomalous position for the testes was ascribed by Garman to D. communis. After having sectioned speci- mens of that species, I find that some of the reproductive organs were misinterpreted by him. Two pairs of digi- tate testes are present in each of the species. These have the usual position, being attached to the anterior septum of each of somites X and XI. In number and position of sperm-sacs the two species agree. There is a pair of pre-septal lobulated sperm- sacs in somite IX, and a pair of pqst-septal lobulated sperm-sacs in somite XII. The latter, in D. communis., were described bj'^ Garman as testes. Somites X and XI are filled with developing sperma- tozoa during the reproductive season, though no definite sacs have been observed. The situation of the sperm- duct in D. riparia is like that in D. communis. The 140 Illinois State Laboratory of Natural History. male pore is also upon somite XIX, in a longitudinal groove, but is near the anterior margin of that somite. Two paii'S of prostate glands are present in each species, having their external openings on somites XVIII and XX. The species also agree in having two ventral crescentic longitudinal grooves (their convexities in- ward), which extend from the middle of somite XVIII to the middle of somite XX, and have modified setae and the external opening of a prostate gland at each of their extremities. In each species somite XIX is with- out ventral setae. On the ventral side of alcoholic specimens of D. riparia, an area extending from the middle of somite XVII to the anterior portion of somite XXI and bounded upon the sides by the two longitudinal grooves, is depressed to a depth of about one fifth the diameter of the worm. In alcoholic specimens of D. communis no such depression is noticeable. Two pairs of spermathecae are present in D. riparia., one pair in each of somites VIII and IX, with the ex- ternal openings at the anterior margins of those somites and in line with the inner rows of setae. D. communis has in addition one pair in somite VII. Although Gar- man makes the possession of three pairs of spermathecae a character of the genus, I feel justified in including the new species in the same genus, especially as other genera of earthworms include species which differ in the number of spermathecae. The ovaries and female pores are in the usual position, the former in somite XIII, and the latter upon somite XIV. The vascular system of D. riparia is much like that of B. communis., except that in no case has any trace been seen of the double dorsal vessel, which is so constant in the latter species. The presence of a double dorsal vessel is included by Garman among the generic characters of Diplocardia, but I think without sufficient reason, since in other instances species differing in this respect are assigned to one genus. Two New Oligochceta from Illinois. 141 The new species, then, possesses all the characters of D. communis which are regarded by Garmau as generic except two; viz., three pairs of spermathecse and a double dorsal vessel. Not regarding these characters as of generic importance, for the reasons given above, I in- clude the new species in the genus Diplocardia, The more obvious external characters bj' which this species ma3' be distinguished from D. comtnimis are smaller size, darker color,—especially of the anterior portion.— the presence of but two pairs of spermathecal pores, and the single dorsal vessel, which in the living- animal is plainly visible through the body wall. For convenience of comparison the following table has been prepared : Diplocardia communis. Diplocardia ripnria. SetaB Prostoraium. Four couples. Patiiary dovetailed lieristomium. A.11 ventral, into Male rore XIX. Testes and funnels X and XI. Speim-dacs. Sacculated in IX and XII. X and XI filled with sper- matozoa without special sac. Prostates Two pairs, with external openings in XVIII and XX. Copulatory fossae or longitudinal grooves. Ovaries Female pore. Gizzards One pair, extending from middl of XVIII to middle of XX, with oopulatory setae and prostate pore at the extiemitles of each groove. One pair in XIII. XIV. Two; in V and VI. Typhlosole ^illght dorsal fold. Subneural vessel i Absent. Nephridia Meganephric . Nephridiopore in line Fourth seta, with I Clitellum XIII-X VIII. Incomplete. Four couples. All ventral. Partially dovetailed into P'^ristomium. Anterior part of XIX. X and XI. Sacculated in IX and XII. X and XI filled with sper- matozoa without special sac. Two pairs, with external openings in XVIII and XX. One pair, extending from middle of XVIiI to middle of XX, with eopulatory setcB and prostate porp at the extremities o' each groove. One pair in XIII. XIV. Two; in V and VI. Slight dorsal fold. Absent. Meganephric. Fourth seta. XIII-XVIII. Incomplete, or but slightly developed upon narrow median ven- tral area. 142 Illinois State Lahoratory of Natural History. Two New. Oligochceta from Illinois. 143- A few points of difference seem to sharply distinguish the two forms. The worms from Illinois are the larger, and have a length, when moderately extended, of 18 to 20 cm. I have alcoholic specimens fixed after being anaesthetized, which, without being unnaturally extended, are over 20 cm. in length, and average .26 cm. in diameter. The arrangement of setee in the two forms differs chiefly in the position of the outer couples, which are in the dorsal half in the new form, instead of in the ventral half as in 8. tamesis* Sections have a quadrangular outline, with a couple of setse at each angle, tlie arrange- ment being similar to that in Criodrilus. The distance between the outer or dorsal couples is one and a fourth times that between the inner or ventral couples in the region posterior to the clitellum, and about one and a half times as great in the region anterior to the clitellum. The distance between the outer couple and the inner couple of the same side is slightly greater than that between the two inner couples. The setse of a couple are quite closely approximated. As in ^6'. tamesis, the outer setae are missing in tiie region where the clitellum is fully developed. Specimens taken late in the season have setae in this region. The sparmatliecal pores are in line with the setae of the outer couple, as in 8. tamesis, but in consequence of the dorsal position of that couple in the new form, the pores are upon the dorsal half of the animal. The form of the region of the clitellum during repro- ductive activity is different from that at other seasons and from that figured for 8. tamesis. At that season the ventral part of the clitellar region, including the ventral setae and the tubercula pubertatis, is slightly con- cave downward, and forms two very conspicuous ridges or actual folds where it meets the lateral walls. This concave appearance, though intensified by the action of alcohol in hardening, is not produced b3' it, but i« present in the living worm. Benham, loe. cit. PI. XIX., Fig. 8. 144 Illinois State Lciboratory of Natural History. The male pores are situ^^ted opposite the anterior part of somite XIX and upon the ventral crests of the ridges, being immediately outside of the tubercula pubertatis, as in 8. tamn.esis. The last point of difference to be mentioned is the most remarkable and unexpected. 8. tamesis belongs to Ben- ham's family Rhinodrilidae, in which, according to him, prostate glands are absent.* There is no mention of any such glands in his paper upon Sparganophilus, yet glands that I consider to be homologous with them are present in the form under consideration. These glands require a somewhat detailed description, since their number and position, and even their occurrence, is rather remarkable. Each gland is tubular and of two well- marked divisions; the true glandular part and the duct. The former is more or less convoluted in an irregular manner, and if straightened out would vary from .5 mm. to 1 mm. in length. Its diameter is fairly uniform, and usuall}' about .13 to .15 mm. In a cross section of the gland the lumen is nearly circular and about .015 mm. in diameter. It is surrounded by an epithelial layer .006 to .01 mm. thick, and outside of this is the layer of glandular cells, which is about .05 to .06 mm. thick. Many of the cells of this layer are club-shaped, and extend from the epithelial layer to the exterior, while others extend only part way through the layer. This part of the gland is surrounded by a plexus of blood vessels from which many minute branches penetrate the gland. The duct has a nearly straight course through the body wall, being but little longer than the thickness of that wall, or about .32 mm., with a diameter of about .06 mm. The inner two thirds has a lumen much smaller than that of the gland and often nearly oblit- erated. It is surrounded by an epithelial layer as in the glandular region, but this is surrounded by a layer of circula-r muscular tissue about .02 mm. thick, which replaces the glandular layer of that region. The outer *"An attempt to classify Earthworms." (Quart. Jour. Micr. Sci., Vol. XXXI., IS'Jl, p. 221.) Two New Ollgocltceta from Illinois. 145 third of the duct has a lumen somewhat flattened and .004 to .008 mm. in diameter, which is lined with a cutic- ular layer continuous with the cuticula of the body wall. Its epithelial layer is also continuous with the epithelium of the body wall, the cells becoming longer in the outer portion of the duct, and partaking of the charactei-s of the columnar epithelium of that part of the body surface which is immediately adjacent to the prostate pores. The muscular layer diminishes in thickness and disap- pears in the outermost portion of the duct. UsuallN' four pairs of these glands are present in somites XXIII-XXVI, a pair in the posterior part of each of these somites opening just outside of the outer setae of the ventral couple. Tne pore and the two setae are nearly in line, and the distance between the pore and outer seta is about one half as great as that be- tween the two setfe. In one example two glands were found in one side of a somite and none in the other, the opening of the second gland being between the setae of the ventral couple, but much nearer the outer one. In another example but three pairs were present—in XXIII XXV. If these are prostate glands,—and I can see no reason to think that they are not,—they are very far removed from the male pore, and are of an unusual number. Benham has called attention to several features in the structure of S. tamesis as being quite remarkable. In these particulars the resemblance of the new form to that species is striking. (1) The sperm duct has the same superficial position and inconspicuous opening, the only difference being that it does not leave its position at the base of the clitellar layer to pass outward until it reaches the septum between XVIII and XIX, where, curving quite abruptly, it opens at the male pore upon the ridge already mentioned and opposite the anterior part of somite XIX. (2) In each species a pair of ovisacs occurs in somite XIV, in which were found ova showing karyokinesis. (3) Longitudinal tegumentary vessels passing forward from somite XIV are present in both, 146 Illinois State Lahoratory of Natural Illdory. being readily seen through the bodj' wall of living specimens of the Illinois species. The dorsal one is con- siderably larger than the other. (4) A perienteric sinus occurs in each species. From the similarity of the characters just mentioned and of others referred to in the appended table, it is evident that the two forms are very closely allied. Were it not for the presence of the prostate glands in the one here described there could be no question about their belonging to the same genus, and, as it is, I do not feel justified in creating a new one, but prefer, for the present at least, to associate the new species with Benham's by naming it Spargaoiophilus eiseni. The chief characters by which it may be distinguished from S. tainesis are, as already mentioned, its greater size, the dorsal position of the outer setae and sperma- thecal pores, the latero-ventral ridges of the clitellar region during the reproductive period, and the presence of prostate glands in some or all of somitesXX LII-XXVI. Necessary figures and additional details will appear in the more complete report to be published later. Sparganophiius iamesis. iSparganophilus eiseni. €litelluin Prostomium Male pore 8perra-sac3 Spermathecae Gizzard and CBsophag eal diverticula. Typhlosole Vascular system Somites XVI—XXIV. with part of XV and XXV. Not marked off from the peristomium by a groove Inconspicuous. Between XVIII aud XIX, without accessory organs. Two pairs; in XI and XII, Simple. Three pairs. Absent. Absent. Perienteric blood sinus. Two long tegumentary ve^^- sels on each side traverse the anterior somites with- out communicating with the alimentary tract. No Bubneural vessel; the only commissural vessels situ- ated anteriorly. XVI-XXV with part of XV. Diminishing on XXIV and XXV. Not marked off from the peristomium. Inconspicuous. Upon an- terior part of XIX. Two pairs; in XI and XII. Simple. Three pairs. Absent. Absent. Perienteric blood sinus. Two long tegumentiiry vessels on each side trav- erse the anterior somites without communicating with the alimentary tract. No subneural vessel; the only commissural vessels situated anteriorly. Two Neio OlkjocJicBta from Illinois. 147 Spnrganophiius tamesis. Sparganophilus eiseni. Clitelliim on ventral surfcioe Lateral setae Alimentary tract Nephridia Nephridiopore Testes and funnels.... JSperm-duct Ovaries and female pore. Ovisacs with ova show- ing karyokinesis Bpermathecal pores... Dorsal vessel Latoral hearts Tegumentary vessels.. Cocoons Length Outer pair of setaa Prostates Continuous but thinner. Absent in fully developed clitellum. Abruptly widens in IX. Large. First in Xltl. In front of seta 1. Two pairs: in X and XI. Subepidermic. In usual position. XIV. In line with lateral setse, which are ventral. Dilated in IX—XI. [n VII—XI; large and monil- iform. In XIV and backward, one pair from each of dorsal and ventral vessels. Sausage-shaped, with one end frayed. 3 to 4 inches (7.5—10 cm.). In ventral haK. Absent. Continuous but thinner. Absent in fully developed clitellum. Abruptly widens in IX. Large. First in XIII. In front of seta 1. Two pairs; in X and XI. Subepidermic. In usual position ' XIV. In line with lateral setso, which are dorsal. Dilated in IX—XII. In VII-XI; large and monil- itorm. Course more tortu- ous than figured for 8. tamesis. In XIV and backward, one pair from each of dorsal and ventral vessels. Sausage-shaped, with one end trayed. 18 to 20 cm. In dorsal half. U^uallv four pairs; in XXIll i-XXVI. Champaign, Dec. 10, 181)4. Since this paper went to press, Michaelsen's descrip- tion of new earthworms from Florida and Georgia* has been received. One species, described under the name Geodrilus eiseni, is very closely related to Dlplocardia riparia described above, but differs in several minor *Die Rpge^'iourrn-Fauna von Florida und Georgii (Zool. Janrb. System. VIII. Bd. 2 Hft. pp. 177-194.) Abth. f. 148 Illinois State Laboratory of Natural History. characters and seems to be a distinct species, Michaelsen states that Garrnan's paper upon Dlplocardia communis was not accessible to him. If it had been, I can see no sufficient reason why he should not have included the new species in the genus Diplocardia. If I am right in not regarding the presence of a double dorsal vessel and of a fixed number of spermarhecae as necessarily of generic importance, and hence in including D. riparia in the same genus with D. communis., then I think the new species ascribed by Michaelsen to the genus Geodrilus really belongs to the^ genus Diplocardia, since it has all the other characters of that genus, as far as can be de- termined from his quite full description, and has no characters that in my judgment are to be considered generically different. I think, therefore, that the new form should be known as Diplocardia eiseni. If Michaelsen be correct in his assumption that Ude's description of Geodrilus singularis was erroneous in cer- tain particulars, and, further, in placing his species in the same genus with that of Ude, then it would seem that G. singularis must also be regarded as a Diplocar- dia. I do not, however, believe that this point can be actually settled until G. singularis can be more fully de- scribed. The following are some of the differences which dis- tinguish D. riparia from D. eiseni: (1) The sperma- thecal pores are in the posterior part of the somite in the latter species, while in the former they are near the anterior margin; (2) the ventral setae of somites VIII and IX are modified in D. eiseni and not in D. riparia; (3) a glandular thickening of the ventral sur- face of somites VIII and IX is present in D. eiseni and not in D. riparia; (4) setae 2, or "b," are present in somite XIX in D. eiseni and not in D. riparia; (5) the first pair of nephridia in D. eiseni is found in somite III, while in D. riparia a pair is present in somite II; and (6) the first dorsal pore seen in D. eiseni is in the first clitellar somite, while in D. riparia it occurs in the an- terior part of somite XI.