KEY TO THE FAMILIES OF ILLINOIS FISHES 3 



xx. Anal spines 1 or 2, never more than 2. 



z 1 . Lateral line not extending on rays of caudal fin Percidae. Page 269. 



zV. Lateral line extending on rays of caudal fin Scisenidse. Page 322. 



ww. Body naked, or variously armed with scales, prickles, or bony plates, never 



uniformly scaled Cottidae. Page 325. 



vv. Chin with a median barbel Gadidae. Page 336. 



