304 



FISHES OF ILLINOIS 



d. 



ee. 

 dd. 



gg- 



ff. 



Lateral line always more or less incomplete, the number of pores lacking 



usually 10 to 30, rarely as low as S. 

 Spinous dorsal fin not exceptionally low, its height as a rule 75 to 90 per 



cent, of height of soft dorsal; no enlarged dark humeral scale. 

 Cheeks and opercles scaled. 

 Rays of second dorsal 9 or 10; scales 55-60; rust-red spots on sides, no bars. 



iowas. 



Rays of second dorsal 12 to 13 ; scales 49-57 ; brown bars on sides. . . . jessiae. 



Cheeks naked; opercles scaled; spring males with alternating red and blue 

 bars coeruleum. 



Spinous dorsal fin as a rule less than 60 per cent, height of soft dorsal; an 

 enlarged dark humeral scale more or less conspicuous. 



Gill-membranes little connected, distances from muzzle to angle and to 

 back of orbit not far from equal. 



Cheeks, opercles, nape, and breast naked; chin, cheeks, and opercles sprin- 

 kled with fine dark dots; a large black humeral scale, its depth § diameter 

 of eye obeyense. 



Cheeks, opercles, nape, and breast covered with embedded scales, chin and 

 cheeks with pronounced dark mottlings and vermiculations ; humeral 

 scale rather small and not very black squamiceps. 



Gill-membranes broadly connected, distance from muzzle to their free mar- 

 gin If to 1+ times that to back of orbit; dorsal spines each ending in a 

 fleshy knob in the male flabellare. 



Fig. 73 



ETHEOSTOMA ZONALE (Cope) 

 (banded darter) 



Cope, 1868, Journ. Ac. Xat. Sci. Phila., 212 (Pcecilichthys) . 



J. &G., 510 (Nanostoma) ; M. V., 130; B., I, 83; J. &E., I, 1075; J., 41 (Nanostoma) - 

 F., 65; L., 28. 



Banded darters which have a superficial resemblance to females of 

 E. cceruleum, and may even be confused (especially in preservative) with 

 E. jessue. From the first this species is easily distinguished by its closely 

 and finely scaled cheeks, and from both, as well as also from all other Illi- 

 nois species of the genus Etheostoma except flabellare, it may be readily 

 separated by the broad union of the gill-membranes. Length ordinarily 

 a little less than 2 inches; body moderately elongate, considerablv com- 

 pressed, the depth 4.7 to 6 in length; greatest width of body" about 

 % its greatest depth; depth of caudal peduncle 2 .4 to 3 . 1 in its length. 

 Colors in life "bright olivaceous above, golden below; 6 dark brown 

 quadrate dorsal spots, which connect by alternating spots with a broad, 



