71 



Hadrnptrnis nspro (Cope it .lordaii). — Hlai-k-sided Darter. (.'{40) 



Sides marked with large blacl^ sfxits. The gill iiiemliranes rather narrdwiv joined across 

 the isthmus, ox erlai)i)iiig or merel.\- joining at tin- front, all gradations lietween tlit-se con- 

 ditions occurring. The edges of the preoijercle not serrate; preiiiaxillary not protractile; 

 mouth large and terminal. 



In rapid streams in all parts of the State. 



Htt<ln>i)tcn(s critics (dordan it Copeland). (.'i4.'{) 

 A few specimens from Kock river in Ogle county, 1877. 

 UaiJiDpteniN sclents Swain. (;i42) 



Oidering distinctly from //. as/>n in the serration of the preopercle and in the liroader 

 connection of the gill membranes across the isthmus. 



One specimen taken from Skillet Fork, in Wayne county. Several others referred to this 

 species are possibly only varieties of //. as/>ni. 



Coltinjdstcr iircniidca (.lordan i<: Gilbert). 



Not identided in our collections, but reported from the lower VN'abash basin, in Indiana, 

 by Dr. Evermann. 



CottogasWr copcUtncll (Jordan). (336) 



(X'curs throughout central Indiana in clear brooks. 



('i)tt(Hittstcr shumardi (tiirard). (336) 



With nuich the appearence of the black-sided darters, (genus Hadroptcri(s\. from which it 

 is separated by the protractile premaxillary. Males with a very (Jeep and long anal tin, which 

 reaches be\ond the base of the caudal in some instances. 



Not common in Illinois. Found in the Wabash river in Wabash county, in the Kaskaskia 

 river at Carlyle and Cowden, twice in the Illinois river, near Meredosia, and five times at 

 Havana. 



Diplcsion hlcniiioldcs (Rafinesque). — Green-sided Darter. (332) 



A large darter, with much decurved profile, small mouth, and large fins; with prominent 

 green markings. One of the handsomest of our darters. 



Confined to the Wabash basin, where it is abundant in the streams of Champaign anfl 

 Verndlion counties, less abundant in the P'-mbarras river and its tributaries, and ijreseiit in one 

 collection from the Little Wabash river in Clay county. C>ccurs in 25 of our coUec-tions. 



Bolcosoma nigrum (Rafinesque). — Johnny Darter. (33.')-326) 



An inconsi icuous little fish; the body slender and of pale straw-color, sprinkled with 

 lirown dots or W-shaped marks. 



The Johnny darter lives in almost all situations, but is most commonlv found on sandy 

 l)Ottoms. Abundant throughout the Stale in all our streams and lakes. Taken in 282 of our 

 collections. 



Boleosomn camitnnn Forbes. (330) 



Differs from B. ni^nm in the more slender body, longer caudal peduncle, and incomplete 

 lateral line. 



Found in southern Illinois and in the Illinois River at Peoria and Henry in early collec- 

 tions. More recently it has been taken from Havana, French Creek at t^rayville, Salt Creek 

 near Lincoln, and Johnny Run in southwestern Grundy county. 



CrystaUitria ctsprclhi (Jordan). (324) 



Form of the head peculiar, much depressed; caudal peduncle very slender; something of 

 the color-markings of the black-sided darters. 



Specimens have been obtained fnmi the Wabash River at New Harmony, from the Mis- 

 sissippi River at East Dubuque and Warsaw, and from the Kock River at Cleveland, Milan, 

 and Erie, large nundiers having been obtained at the latter place, (jenerally rare; unusual to 

 take more than one in a place. 



Ainmi)cr]ipt(( pcllucida (Baird). — Sand Darter. (322) 



Body translucent in life; on eacii side a row of black spots. Scales absent from the belly 

 and inconspicuouselsewhere; cheeks, opercles. and temporal regions scaled. These fish will 

 instantly bury themselves in the sand by a swift movement. 



Not rare in the Wabash basin. from which we have si)ecimens in 13 of our collections. 

 P'ound also in the headwaters of the Kaskaskia. in the Sangamon and its tributaries, in Crooked 

 Creek near Ripley, Spoon River near Lew i^town. Bear Creek near Marcelline, Otter Creek at 

 Streator,and the Kishwaukee Kixerat New Milford. 



KEY TO ILLINOIS SPECIES OK THE GENUS ETHEOSTOMA. 



a. Lateral line complete. 



b. Gill membranes joming in a wide angle or curve acrcxss the isthmus E. zonale. 



bb. Gill membranes scarcelv connected; muzzle decurved as in Bolcosoma. 



v.. camukt.m. 

 aa. Lateral line more or less incomplete, or, if complete, the gill membranes joining at an 

 acute angle across the isthmus. 



c. Angle lietween gill membranes acute; membranes joined across in some cases; 



lower jaw not projecting. 



d. Humeral regiim without a distinct black scale-like process. 



e. Cheeks and opercles scaled. 



