304 FISHES OF ILLINOIS 



c. 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. 



d. Cheeks and opercles scaled. 



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



i owae. 



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



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



bars coeruleum. 



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



enlarged dark humeral scale more or less conspicuous. 



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



back of orbit not far from equal. 



g. 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. 



gg. 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. 



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

 gin 1% 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 



(Map XCIII) 



Cope, 1868, Journ. Ac. Nat. Sci. Phila., 212 (Poecilichthys). 



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. 

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

 jessice. From the first this species is easily distinguished bj^ its closety and 

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

 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, considerably compressed, 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, brown lateral band, from which 



