INHSBullv4artX • • ARTICLE X.-IJescriptions of New Spedes of Rotifera and P rotozoa from tlie 1 tti1iois River and .Adjacent Waters. BY ADOIJl:'H H E MPEL. In April, 1894, the Biological Experiment Station of the University of Illinois was established on tl1e Illinois River at Havana, Illinois . Collections were made from various substations, located upon the river and adja­ cent lakes, at stated periods, the intervals va1·_ying from one week to one month. Nearly all of the to,ving·s made were examined by me, and t he list of animals includes ninety species of Rotifera and eighty species of Prot ozoa. Among the Rotifera there are three presumably hit herto undescribed species of the genus B racliionus. This genus is v\~eJl represented by ten species and tvvo varieties, and affords an interesting field for study. ROTIFERA. B1·acliior1.lu,s vMiabitis n . sp. (Plate XXII., Fig. 1 and 2.J This species ii:i remarkable becat1se its posterior spines disappear ,;vith age. The lorica is smooth and oval in outline. There are six occipital spines, of vvhich the middle pair are longest and are curved out,vard. The second and third J)air are of abot1t equal length, and half as long as t he 1nid­ dle pair. rrhere are usuall_y two lateral posterior spines present, vvhich have a Rlight out"vard curve. A square plate projects from the dorsal posterior edge just over the foot or·ifice, and is a constant feat11re. The outer pair of occipital spines are strengthened by a sharp spine-like reinforcement at their ba,ses. The pectoral edge is very irregular. The1·e is a sinus in t he middle, at each side of vvhich is a papilloo-like process. Between these processes and t he latera l spines, there is ]\Tew Species of' Rotij(j'J·ct ctr1,d P,,otozou. 311 a deep sinus on each side. The surface of the lorica i::i marked by sbo1·t r1dges running· bacl{ from tl1e s1)ine::; and median processes. The posterior spines are about one fifth the length o the lorica. In many specimens, e .. pecially old ones, these spines a1·e quite short, and in son1e instances the.v are entirely ,vanting. So far as observed, tbe ne,rl.v batched young and embrJ'OS in the eggs all possess tbe posterior spines, this indicating that the spines a re characteristic of the species and are shed or absorbed only in old a.ge. Tbe quad1·ate l)late over t l1 e foot orifice may ser·ve as an easy means of identification, since I know of no other mem be1· of this genus t l1 at, bas a sirnilar st1·uctu1·e. The eggs are car1·ied abot1t fast­ ened to the posterior part of t h e lo1·ica. The internal structure of this rot ifer is normal. There is a large subquadrate dark-1·uby eye just in front of the mastax. The foot and two toes a re sn1 all for such a large species. Le11g·th of lori ca, including :--;pines, .34-2 min. to .418 mm.; ,Yidth .209 mm. to .257 m m. This species was found in to,rs fro1n the Illinois Rive1· ' Qui\·er Lake, Tl101n1)son's Lak:e, a nd Phelps L al{e. It is very 1·estless and ucti ve, and occurs only in open "·ater, free from vegetation. Brachio1i1.£S pur1.ctatus n. sp. quadrate, sides slight]y ron\·ex. ~\. c1·oss section ,,·ould be nea1·Jv ei1·cular. u Fo11r occipital spines of abot1t equal lengtl1, cu1·v_ ing ~lightly do,Yn,,·ard and out,,·ard . In the lt1mbar reg·ic)n there is a slight invagi.nation of the lorica on eacl1 ·icle, thus causing blunt angles on the surface of the lorica, a nd rnaking it irregular. The entir·e surface and spine. are covered ,,·ith minute spinules. The surface of the lorica is also marked off i11to areas by severa! cur,-ed lines. There are no posterior spines. 312 l lltnois })"tate Laborato1·y of N atural History. 'fhe posterior part is slightly excavated on the dorsal and ventral Sl1rfaces around the foot, th~ ventral exca­ va tion being more pronounced than the dorsal. The pec­ toral edge is slightl.Y indented jn the center, the edges sloping ur1iformly from the late1,al eflges to the middle. A small rer:l eye is situated just in front of the la1·ge mastax. A dorsal antenna is prominent 1n the sinus between t he antlers . . The foot is long a nd wholly re­ tractjle. The eggs are carried about fastened to the posterio1· part of the lorica. The characteri8tic features of t his rotifer are the shape of tl1e lorica, the latero-posterior inangulations, t.he shape of the occipital spines, and the Rmall spines covering the surface of t he lorica. Its nearest ally is B. budapesti­ nensis Daclay (PJa,te XXIII., Fig. 6), from which it differs in tl1e form of the lorica, in the size and shape of the occiJ)it al spines, and in the shape of the foot orifice. This is a lively Ii ttle species, and is found only j n clear water, avvay from vegetation. Lengtl1 of lorica, includ­ ing spines, .151 rr1m. to .172 n11n.; ,vidth .092 1nm. to . 096 lll lil. B rachio1ius mollis n. sp. (Plate XXIV., Fig. 7 and 8.J Lorica t hin , smooth, oval in outline; the dorsal surface l1ighJy arched; ventral surface but slightly convex. The anterior margin straight and truncated. No occipital or posterior spines. A. very prominent dor­ sal antenna near the anterior margin. This species is peculiar in having a very thin, soft lorica and no spines . When the animal contracts, it freque11tly invaginates those parts of the lorica that serve ai-; attachments for the muscles. 1"be foot ori­ fice is guar,jed by a collar. 'rhe. foot is very large and long, is ,vholl_y retractile, and ends in two small toes. The toes are very characteristic for this species. Viewed either dorsally or latera1ly, they taper to 1."'\~e10 Species of R otifl3J'a [tnd P,·otozoa. 313 very fine points. Tl1eir inne1' edges are convex ~111c.l :-:eparated fro111 each other, ,,·bile the oute1' edges ,1re conca,Te, consequentl.v ,v hen vie"·ed L1orsal1:)T, tlie toes are een to be se1)aratec1 and to cur,re awaJ· fron1 each . - otl1er. ..1 1·uby ej·e i~ ~it11ated i11 front of tl1e large 111ustax. The ovary is larg·e and SJ)herical. Tl1e stom­ ach, vie,vecl dorsally, is J)ear-sl1a1)ecl, with ]arg·e encl to­ wards the anterior part. 1~he eggs are c.;a1·riecl abot1t fas t ­ ened to the poster ior part of tl1e lorica. Wl1en the animal witbdra,,·s into the lorica, the ante1·ior edg·e is thro,vn into a nt1m ber of longituc1inal p]ications. This ·pecies "'as found c.lu1·iug J ul5· and .1ugt1st in tows from tbe I11i11ois Rive1' and PhelTJR LakP. L e11gtb of lorica .228 n1w.; n·i,lth .150 1n111. PROTOZOA. OE t he eigl1t.,~ SJ)eries or I>L'otozoa observed. fot1r ap­ pear to be ne,v to sc·ienre. T,vo of t hese, D t:ffez1gir1 tltr berc1tlosa, and Ce1'atii1,m brevicotne, were first found in Matanzas Lake. n;jfl1tgia t1,berc11,losa n . sp. (Plate XX V .. Fig. 9 and 10.l • Shell compressed, irregula1'ly ovoid in shape, sl'g1Jt1s const1·icted around the 1not1tb, an c1 JJro1ongetl into a short neck. .r"'undt1s 1·ou11c1ed , and endiug in 011fl or more blunt processes, like D. pyrifo1'mis val'. 1iu(Wsa Leidy. On each of the co111prei;sed sides the1'e a,·e three small p1·ominences or tu ber·cles. This is a medium-sized si)ecies, abo11t one and a fourtl1 ti 1nel:; a long as ,vide. The shell is compo~ed of larp;P anrl small rounded sancl g·rains. ~o diatoms a111l uut ,ery fen· grains of sanu. \Yith sha1·1J corners ar'e found in the shells. rrhis sper·ies is characterized by having three small tuberrle:a- on eacl1 of the two co1n­ fJre~sed side.·. These tu l1Prrles are arrang·ed o n eacl1 side of the i;hell so as to fol'rn tl1e a.ogle~ or a triangle. • 314 I ltinois State Labo,·atory of Naturat History. One is near the edg·e of the fundus, and the other two are J)laced one at each side of the shell a little above the neck. Alt houg h the shell itself varies greatly- in outline ancl is asymmetrical, these tuberrlcs are c.onstant and affo1·d a n easjT means of r·ecognizing the species. The pseudopodia are simple and few in number. Length .143 rnn1.: vvidth .111 mm. This Rpecies ,;vas fou nd in t o,vings taken in i1atanzas Lake during August. It was not common, and we have seen it but once since. Oe1·atvt1l111, brevicorne n. s1J. (Plate XXV., Fig. 11 and 12; Plate XXVI., Fig. 13.) Bocl3r small, con1pressed, triangu lar; three spines, one anterior and t,,o posterior, the left posterior one quite small. ,.rhe surface is slightly rougbened by the small plates, but there are no small spines. The long anter·ior spine smooth. This is a compact robust little species, about two and a half times as long as wide. The shell is curved so as to be convex on the do1·sal surface and concave on the ventral. The t hree horn-like processes or SfJines are strajght prolongations of the shell; no specin1e11 was fot111d in vvbich t hey were bent or curved. Length, in­ clt1cling· spines, .115 mrr1.; width .046 mm. This is a rather rare form. I t \Vas found during Au­ g11st in tovvings from A1atanzas Lake, in con1pany wit h P ei,idi?ivu11i tabulatu1n Ehrbg., and has been observed only at ra re intervals since. It can be djstjnguisl1ed very r·eadily by its compact tria11g·ular body and short st.raight spines. Ti1ztinriopsis illin.oisensis n. sp. (Plate xxvr., F ig. 1-1 auct 16.l i.\.nimal small, ova.te, i1Jbabiting a narrovv cylin­ d1·ical or thim ble-shaperl chitinous shell, covered for tl1e most part nrit h s 1na ll sharp-a11gled gra.ins of sand. li'undus outl1sely conical or rounded. Shell either of the - • .lt..,.ew Species of .Rotifera and Protozoa. 315 same diameter throughout, or sljghtly dilated at ora1 opening. Sides straight, more than twice as 1011g as wide. 1~l1is pecies ag1·ees very closel.)· ,,itb T beroidea Stein, anJ I place it here provisionally until its minute strl1C­ tu1·P can be more closelj· studied. The shape of the lorica is characteristic: long. na1·1·ow, with straight sides, often slightly dilated at the 111outh, and frequently ,,ith a bluntly conical fundu , givi11g it the shape of a rather 1011g thimble. It is s1naller tl1an T. beroidea; its aver­ ag·e leng·th being .059 ruin. and the average "'idth .029 ID Ill. It "·a·· found in Ar)ril and ~lay, in company ~Yith C1,rl/)1ielta cratera Leicly, in ton·s from t he Illinois River, ':l'hom pson's Lake, and Quiver Lal{e. O_pe,·cula,·ia i,1·itc1b£l-is n sp. (Plate .S..S.,f., Fi~. 17 and 18. J Body ovate, elongate. t1'l1ncated posteriorly, two and a 11alf tin1es as long as "'ide. Greatest diawe­ te1· in f1·ont oi the middle, n·om ,vhence the sides ·lope grauually fro1n the poste1·io1· end. Pe1·istorne border e,· rted, thickened, forming a conspicuous ridge or 1·ing; conbtrie:ted belo,r the borde1·. Ciliary oi::;c slightl;y dome-shaped, not highly elevated; tn·o ron-s of cilia pre ·ent. The cuticular surface is s111ooth. Endoplasm granular, ,ve1lo,nsb. Contrac­ tile vacuole large, circular, l)laced in the ante1·ior part, near the IJeriston1e. Nucleu::, band-like. curved, placed transversely in the ante1·ior J)art of the bocly. The zooids are ,erv sensitive, and when cont1·acted ~ they have an oval shape; the anterior part is projected jDto a snout-like }Jron1inence and tliro"·n into numerous longitudinal folcls; n·bile the posterior part is ront1·acted a1·ol1nd the base ot the pedicle, and thrown into trans­ verse }Jlication. . The n1etnbranous collar is not ,ery con picuous. The pha1·)·nx is la1·ge, extends half the 316 I tli1iois State L ctborctto·ry of l17atitrctl H istory. length of t he bod j', and is lined \Vith cilia. The P.ndo­ plasm in t he pos te1·ior part of t he body is clear, and numerous fine lo11gitudi11a l stria t ions can be - cliffereL1- t ia t ed . rl'hese unite and form the core of the stalk, ,Yl.iich h as also fine longit udinal striat ions. 1'he stalk i8 va1'iously branched. Some of the zooids have long pedicles, "~hile others are nea1'ly sessile. The colooie8 are large, consist ing of several hundred individuals. l\ful­ tiplication by longitudinal division was noticed. Length, .178 mm. to .20 mm.; \Vidth .078 mrn. Thi ::; RJ)ecies is similar to Upercuta,·ia articuLata Eh1'bg., but cliffers fro·m it in the sha pe of the body, t he charac­ ter of t he peristome border and pharynx, and t he ele­ vation of t he ciliary d1sc. I t ,vas found during t.he sum mer 1nonths at many of the stations , always attached to some animal, and see111 ed to prefer the young musk turtle, Aromochetys odorctt'lts. It also occurr·ed o n the backs of the snapping turtle, Ohelydira serpe1iti,ict, and the crayfishes Oa;mbarus dioqenes, a nd 0. blcvridi11,gi-i var. acitta. Tokophrya quawri_partita C. & L. ,vas found common in cornpanywith this species, a,s was also a small Opercularia ,vr1ich rr1 ay t-t1rn out to be a variety . The zooids are small-length .08 mm.; ,vjdth .042 mm.-but otherwise they seem to agree with the larger species. A part of the food of this spGcies consists of diatoms and Eugleria. Collections are still being made at the various stations, and ft1 rt her study will no doubt add other forms to .. this list. H avana, May 12, 1896. • • EXPI-'ANATIOX OF PL1\TES. PL,.\'f' E XXII. Fi p:. 1. B ,·achion,tf;8 va,, icto il is n. sp. E'ig·. 2 . '' va1·1.·c1bilis n. sp. Form without pos Fig. }-,ig. l"ip:. Fig. Fig. Fig·. Fig. Fig. terior s1)ines . PLATE :S::XIII. 3. B rachionus pz1,1ictati1,s n. sp. Lateral view. 4. '' _purictcttits n. sp. DrJr Hc.11 vie,,·. 5. '' pz1,1zctrtt1ts n. sp. ,c\nterior aud l) OS- terior encl:::; of lc)rica. 6. Bracliion'l.tS budr11Jesti1ie11sis Daua3r. PL,c\TE XXIV. 7. B 1·achionus 1r;.ollis n. sp. 8. '' rrio7lis n. SJJ. DorRal vie,v. L ctteral view. 9. 10. 11. 12. 13. 14. 15. 16. Pr.,~\.TE XXV. D ijftitgia titbe,·cttlosct n. sp. ' ' t1tberc11,l osc1, n. s p. C'eratiuni b1·evicorne n. RTJ. '' brevic01·11e n. sp. PLATE XXVI. A not ber form. Ven t1·al vie,v. Dorsal vie\v. Oe'rati1.em brevicorne n. sp. Lateral vie\v. Tintirllnopsis illi,ioisensis 11. s1) . '' illinoi8e,,.sis n. sp. Another forrr1. '' illi11oisen::;is n. sp 4\..nother fol'n1, not so n1uch magnjfied. Fig. 17. Fig. 18. Operc1.tl(J;ria i1·1·itr,uil is n. sp. Expa1Jclecl zotiid. cc i,,ritctbilis n. SI), Co11trn cteu zooid. • Fig. l. • • .. .. . .. . . .. • • • ', . . . . . · . . . . .. . •, ' .. •' .. .. . . . · . . . . . • .. ... . . -. .. . . . . . , . . .. . . • . . .· .. .. ... ~ . . . .. . .. . .. • . . . . '. .. • . . . .... .. . • • • ' . i • . · .. . . .. . . . . . . .. . . . . • • • . . • • • , .. . .. .. -!. . . . . . .. , . , . . . ' PLATE XXIII. . . . . .. . . . . .. .. . . . . .. • • .. • • .. .. • . . . • .. ' . •' . • • • • • Fig. :~ . Fig. D. . . . ' ' . ' . . . .. . . . . . . • .. • ' ' • • • • • • • • • • • • • . . . • • . . . . . . • • • • • • • • • • . . . • .. • • • . . • • • • • • . .. ' ' • • . . .. •, •· Fig. 6. • • • • I j PLATE XXlV. Fig. 7. Fig. . • • - • • • • - Fig. 9. Fig. 10. I Fig. 11. Fig. J 2. • • PLAT E XX\TJ. _1/ .b' ig. 13. • . L Fig. 1-:1:. ' Fig. Li. Fig. l 6. 4 ., ✓ f I . ' , .I ✓ I t._ ) ' ., . rr ~ .. .. , • , .. ,, Fig. 15. Fig. 18. l l