302 PISHES OP ILLINOIS 



band" (Jordan and Evermann). Head 4.1 to 4.4 in length, its width 2 to 2.5 

 in its length, interorbital space narrow, concave, 7.1 to 8.4 in head; eye 3.6 

 to 4.3; nose decurved, pointed, 3.1 to 3.8 in head; mouth moderate, maxillary 

 extending to front of orbit; cleft 3.1 to 4.4 in head; lower jaw slightly shorter 

 than upper; gill-membranes somewhat connected, but forming a sharp angle, 

 the distance from muzzle to angle about \y times that to back of orbit. 

 Dorsal fin IX-XI, 9-11 (usually IX or X); spinous and soft portions widely 

 separated, the space greater than width of eye; height of first dorsal low, 2.2 

 to 3.5 (usually less than 3) in head, second 1.8 to 2.1 (height of first 56 to 

 80 per cent, of second); caudal fin lunate; anal I, 8 or 9 (occasionally 7); 

 pectorals 1'to 1.3 in head; separation of ventrals less than the width at base. 

 Scales 6 or 7, 67-78, 8 or 9+, the upper and lower rows (nearest back and 

 belly) sometimes lacking, body being naked except for a strip along the side 

 of varying width; lateral line usually complete; cheeks and opercles scaled; 

 nape scaled or naked; throat, breast, and belly entirely naked; all scales more 

 or less embedded and with edges little ctenoid. 



FIG. 72 



This extremely interesting fish, peculiar in its very slender 

 form, its semi transparent body, and its habit of living much of 

 the time in the sand, with only its eyes showing at the surface, 

 make it one of the most remarkable cases of special adaptation 

 in this highly adaptive little group. Situations favorable to its 

 habits are so rare in Illinois that its comparative scarcity here 

 was to be expected. It has been found by us twenty-nine times, 

 in localities well distributed twelve of them from the Wabash 

 Valley, one from the lower Kaskaskia, six on streams of the 

 lower Illinois, one on a creek of the Mississippi bluffs, and three 

 on Rock River or its tributaries. It is reported by Jordan and 

 Evermann from Lake Erie to Minnesota, Kentucky, and Texas, 

 occurring usually in clear sandy streams. 



An excellent account of its habits and peculiarities is given 

 in Bulletin 47 of the United States National Museum by Jordan 

 and Copeland. The fish has a very sharp nose with an exceed- 

 ingly slim and round body, as transparent as jelly but hard and 

 firm to the touch. Its belly and much -of its back are quite bare 

 of scales, and those along its sides are small and inconspicuous. 



