ETHEOSTOMA 307 



late-summer color much lighter, fall specimens often suggesting Boleosoma 

 nigrum. The large size and peculiar shade of the rusty-brown to rusty-red 

 blotches will usually serve for the recognition of this species. Head 3.7 to 

 4, less pointed than E. jessicc, the muzzle rather blunt, scarcely decurved; 

 width of head 1.8 to 2.1 in its length; interorbital space not much wider than 

 half of eye, 6 to 8 in head; eye nearly round, 3.3 to 4.4 in head; mouth rather 

 small, nearly horizontal, subterminal, maxillary reaching to front of orbit; 

 cleft 3.6 to 4; lower jaw included; gill-membranes scarcely connected, dis- 

 tance from muzzle to angle usually less than 1.1 times that to back of orbit. 

 Dorsal fin VIII— XI, 9 or 11; spinous and soft portions separated by a space 

 somewhat greater than diameter of eye; height of first dorsal 2.1 to 2.7 in 

 head, second 1.8 to 2 (height of first 68 to 94 per cent, of second); caudal 

 truncate or very faintly lunate; anal II (occasionally I), 6 to 8 (usually 7); 

 pectorals 1.2 to 1.4 in head; separation of ventrals always less than half, 

 sometimes only ^$, their width at base. Scales 5 or 6 (occasionally 7), 

 55-60, 7-9 [10-12], lateral line somewhat flexed upward anteriorly*, as in 

 E. jessioe; about 25 pores usually lacking; cheeks, opercles, and nape fully 

 scaled; breast naked; belly covered with ordinary scales. 



A rare species in Illinois, taken by us from eight localities, 

 all in northern Illinois except one from Johnson county. The 

 following are the recorded places: Pistakee Lake, in McHenry 

 count}'; Wolf Lake, South Chicago; Senachwine Lake, Henry 

 county; Rock River at Milan, Rock Island county; Green 

 River, near Geneseo, in Henry county; Pecunsagan creek, near 

 Utica, La Salle county; Illinois River, at Ottawa; and Dutch- 

 man's creek, near Vienna, Johnson county. 



Its known general range is northward at least as far as 

 Qu'Appelle River in Assiniboia, westward to Valentine, Neb., 

 and southward to Arkansas. 



ETHEOSTOMA JESSUE (Jordan & Brayton) 



(Pl., p. 306: Map XCIV) 



Jordan & Brayton, 1877, Jordan's Man. Vert., 227 (Poecilichthys). 



J. & G., 518 (Poecilichthys); M. V., 133; B., I, 72; J. & E., I, 1084; Forbes, in J., 

 41 (Poecilichthys asprigenis); F., 64 (asprigene); L., 29. 



Length ordinarily a little less than two inches, though specimens are 

 occasionally found 2^ inches; depth 4.8 to 5.4 in length; body as a rule con- 

 siderably compressed, its greatest width about % of its greatest depth; dor- 

 sal and ventral outlines usually about equally arched, giving the fish a 

 symmetrical, bass-like form, which appearance is aided by its rather large 

 and oblique mouth; depth of caudal peduncle 2.1 to 2.6 in its length. Color 

 brownish olive, the back with 5 or 6 quadrate saddle-like blotches of blackish 



* In E. jessice and iowce the lateral line is nearly parallel with the line of the back. The 

 difference between these species and Boleichthys fusiformis in this feature seems to be in the 

 rtoseness of lateral line to the back at its highest point rather than in the matter of parallelism. 



