310 FISHES OF ILLINOIS 



with 11 or 12 bars of dark indigo-blue color, the interspaces between the 

 bars blood-orange, brightest backward, as are also the indigo-bars; head 

 flesh-color, with lavender on chin and yellow to orange on opercles; forehead 

 and top of snout dull bluish black; a blue splash below eye and a dark spot 

 behind it; spinous dorsal crossed at its middle by a row of orange-red spots 

 in an orange band; above and below this a pale to deep indigo-blue band; 

 at base of fin a narrow band of orange with a central row of orange-red spots. 

 Females duller in color than the males, the bars dusky and interspaces olive; 

 spinous dorsal with a narrow outer edging of pale blue, next to which is a 

 straw-colored band with a row of rust-colored spots, in place of the orange 

 of male. Head large, 3.6 to 4 in length, the profile in males a broad and 

 practically continuous curve from front of dorsal to tip of snout; females with 

 nape angled; width of head 1.7 to 2.1 in its length; interorbital space flat, 

 about 2 /i of eye, 5.8 to 7.2 in head; eye nearly round, 3.7 to 4.1; mouth 

 moderate, terminal, somewhat oblique, tip of upper lip nearer to floor of orbit 

 than base of chin; lips rather large, upper with great lateral depth when 

 closed; maxillary reaching to front of orbit; cleft 3 to 3.5; jaws subequal; 

 gill-membranes scarcely connected, distances to angle and to back of orbit 

 about equal. Dorsal fin X (or XI), 12-14; spinous and soft portions scarcely 

 separated, or slightly connected at base; height of first dorsal 2.1 to 2.7 in 

 head, second 1.5 to 1.9 (height of first 67 to 83 per cent, of second); caudal 

 truncate; anal II, 7 or 8 (occasionally 6) ; pectorals 1 to 1.2 in head; separation 

 of ventrals usually about }A, their width at base. Scales 6, 44-51, 7 or 8, 

 occasionally 6 [9 or 10]; lateral line flexed slightly upward anteriorly, 15 to 

 20 pores usually lacking; cheeks naked; opercles scaled; nape scaled poste- 

 riorly, usually naked in a small patch next to occiput; breast naked; belly 

 covered with ordinary scales. 



Fig. 74 



The rainbow darter, one of the most brilliant of its group 

 and closely allied to Etheostoma jessice, is less abundant in this 

 state than that species — occurring in 99 of our collections to 

 161 of the other — and differs widely from it in local distribution 

 also, especially in an avoidance of stagnant waters and the 

 larger streams. Indeed, we have taken it but three times from 



