PIMKP1IALES — FATHEADS 117 



and in the streams of the Ozark region in northern Arkansas. 

 It is also reported from the Northwest as far as Wyoming. 



Genus PIMEPHALES Kafinesque 



FATHEADS 



Body robust or elongate, little compressed; head short and rounded; 

 mouth small, inferior; upper jaw protractile; no barbel; teeth 4-4, with 

 oblique grinding surface, usually but one of the teeth hooked; intestinal 

 canal more than twice length of body; peritoneum black; dorsal rays 7 or 

 8; anal rays 7: the first (rudimentary) dorsal ray in males evidently separated 

 by membrane from the second, and not adnate to it as usually in minnows; 

 scales rather small, 43 to 47 in lateral series; lateral line complete or im- 

 perfect. Size small, 23^ to 4 inches. Two species, generally distributed 

 throughout the United States east of the Rockies. 



Key eo the Species or PIMEPHALES found in Illinois 



a. Body short and stout, depth 3 to 4 in length; lateral line more or less in- 

 complete promelas. 



aa. Body moderately elongate, depth 4 to 5 in length; lateral line complete 



notatus. 



PIMEPHALES PROMELAS Rafinesque 



BLACK-HEAD MINNOW; FATHEAD 

 (Pl., p. 128; Map XXVII) 



Rafinesque, 1820, Ichth. Oh., 53. 



G., VII, 181; J. & G., 158; M. V., 55; J. & E., I, 217; N., 45; J., 55; F., 79; F. F., 

 I. 6, 78; L., 14. 



Length 23^ inches; body robust, short, thick and deep, much heavier 

 forward, not notably compressed; depth 3.2 to 4 in length; caudal peduncle 

 stout, its length about same as head, its depth usually less than 2 in its length. 

 Color rather dark olive, with a tinge of coppery or purplish forward; dorsal 

 fin with a dusky cross-bar about the middle, faint in females and young, but 

 appearing as a large jet-black blotch covering most of the lower two thirds 

 of the fin in spring males; other fins plain in females, in males all more or less 

 dusky, pectorals and anal most so; spring males often found in which almost 

 the entire body is dusky, the head in such instances being a jet-black.* 

 Head 3.6 to 4 in length, very broad, short, and blunt, sometimes appearing 

 almost globular in breeding males; width of head usually great (see Cliola 

 ligilax), 1.4 to 1.7 in its length; interorbital space broad and nearly flat 

 (except in spring males, in which it is swollen), 2 to 2.5 in head; eye 4.1 to 

 4.8 in head; nose longer than eye, 3 to 3.5 in head; mouth rather small, 

 subterminal and quite oblique in females, in which the tip of the upper lip 

 is nearly on a level with the upper margin of the pupil — less oblique in males, 



* Males taken from Kickapoo Creek at Elmwood in June, 1900, have the head jet-black, 

 and all the rest of the body an extreme dusky with the exception of a broad transverse bar of 

 lighter color just back of and tipping the opercle and a similar bar which passes around the sides 

 directly beneath the dorsal fin. 



