28 



Pound 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 Grayville. Salt Creek 

 near Lincoln, and Johnny Run in southwestern Grundy county. 



Crystallaria asprella (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 from the Wabash River at New Harmony, from the Mis- 

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

 and Erie, largre numbers having been obtained at the latter place. Generally rare; unusual 

 to take more than one in a place. 



Ammocrypta pellucida (Baird). — Sand Darter. (322) 



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

 and inconspicuous elsewhere; cheeks, opercles, and temporal regions scaled. These flsh 

 will instantly bury themselves in the sand by a swift movement. 



Not rare in the Wabash basin, from which we have specimens in 13 of our collections. 

 Found also in the headwaters of the Kaskaskia, In the .Sangamon and its tributaries, in 

 Crooked Creek near Ripley, Spoon River near Lewistown. Bear Creek nearMarcelline, Otter 

 Creek at Streator, and the Kishwaukee River at New Milford. 



KEY TO ILLINOIS SPKCIKS OF THE GENUS ETHEOSTOSIA. 



a. Lateral line complete. 



b. Gill membranes joining: in awide angle or curve across the isthmus. ..E. zonale. 

 bb. Gill membranes scarcely connected; muzale decurved as in Boleosoma. 



E. CAHUBDM. 



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

 at an acute angle across the isthmus. 



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



lower jaw not projecting. 



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



e. Cheeks and opercles scaled. 



f. Scales about 60; soft dorsal of 10 or 11 rays E. low^. 



ft. Scales 47 to 55; soft dorsal with 12 to 14 rays; lateral line almost complete. 



E. JESSI.S. 



ee. Cheeks naked; opercles scaled E. ccebulium. 



dd. Humeral region with a distinct black process or scale. 



g. Scales in about 50 diagonal rows; lateral line developed on less than 30 scales. 



h. Cheeks naked; opercles scaly E, tippkcanoe. 



hh. Cheeks and opercles naked E. obeyense. 



eg. Scales in about 60 diagonal rows; lateral line almost complete E. squamicbps. 



CO. Gill membranes joining broadly across the isthmus in a gentle curve (no angle), 

 body slender; head pointed; lower jaw projecting; first dorsal in males with 

 fleshy knobs on ends of spines in breeding season E. flabellare; 



Etheoatoma zonale (Cope). 



Readily distinguished from other darters of this genus by the broad connection of the 

 branchiostegal membranes across the isthmus. Body in spring with bands of greenish, 

 which become bluish in later summer. 



By far the greater number of our collections of this species come from streams north of 

 the upper course of the Illinois River, including the Rock River basin. In addition we have 

 one collection from the Little Fox River in White county, a few from streams in Woodford 

 county, and some from the Vermilion River and tributaries in Livingston and LaSalle 

 counties. 



Etheostoma camurum (Cope). — Blue-breasted Darter. 



Highly colored, "perhaps the prettiest of fresh-water fishes." 



Early collections of this species appear from Peoria, from Union county, and from the 

 Saline and lower Wabash basins. A da'ter which belongedapparently to this species, taken 

 more recently by Mr. J. P. Bauer, of the U. S. Fish Commission, from a pond near Naples. 

 111., was brought into the laboratory at Meredosia and inadvertently lost before the prelim- 

 inary identification could b^ verified. 



Etheostoma iowce Jordan & Meek. \ 



I The males of this species are strikingly marked on the sides and on the spinous dorsal 

 with dark brown and rust-red. The females are plainer, with olive bands, and bear 

 some resemblance to the females of the rainbow darter. 



