150 FISHES OF ILLINOIS 



FIG. 37 



(MAP XLII) 



Forbes, 1878, Bull. 111. State Lab. Nat. Hist, I. 2, 60 (Episema). 

 .J & G., 194 (Minnilus); M. V., 60; J. & E., I, 290; F., 77; Lr., 18. 



A pale silvery minnow of rather indefinite characters, in form resembling 

 Hybognaihus nuchalis, the outline being fusiform, with dorsal and ventral 

 contours similar, but lacking the long intestine and maxillary protuberance 

 of that species and with the head rather blunter. Length 2 to 2}/ inches; 

 depth 3.8 to 5 in length, the body deepest just in front of the dorsal fin; 

 body considerably compressed, the greatest width about Y% the greatest 

 depth; caudal peduncle somewhat shorter than head, its depth 1.9 to 2.4 

 in its length. Color pale, the sides silvery with a broad plumbeous band; 

 lateral scales rather coarsely specked with black, those of back more finely 

 specked over their entire surfaces; cross-hatching most evident along lateral 

 line and below it, where the scales are pale except at outer edges; a dark 

 vertebral streak but no caudal spot; cheeks and opercles silvery below, steel- 

 blue to cerulean above; a conspicuous splash of emerald on lateral aspect of 

 occiput just behind eye; iris silvery with some lavender; fins all plain. 

 Head 3.8 to 4.5 in length, squarish in transverse section at orbits, being 

 only slightly rounded above; width of head 1.7 to 2.2 in its length; interorbital 

 space 2.5 to 2.9 in head; eye very little shorter than snout in adults, 3.2 to 

 3.8 in head; nose bluntly conic, 3.1 to 3.6; mouth moderately large, very 

 little oblique, the tip of the upper lip little above level of lower rim of pupil; 

 maxillary 2.8 to 3.4 in head, extending hardly to front of orbit; lower jaw 

 slightly shorter than upper; isthmus less than pupil. Teeth usually 2, 4-4, 

 2; sometimes 1, 4-4, 1 or various intermediate combinations; grinding sur- 

 face, if present, narrow and irregular; intestine .9 to 1.2 times length of head 

 and body; peritoneum silvery, with a few small specks of dark color. Dorsal 

 fin with 8 rays, occasionally 7, set as a rule almost directly over ventrals 

 and about equidistant between muzzle and base of caudal; longest dorsal 

 ray 1.1 to 1.4 in head; anal rays usually 7, occasionally 6 or 8; pectorals short, 

 1.1 to 1.4 in head, as a rule less than % to ventrals; ventrals falling distinctly 

 short of vent. Scales 5, 34-37, 3 or 4; rows before dorsal 13 to 15; scales 

 rather large, thin, and round; lateral line little decurved. 



