40 UNIVERSITY OF COLORADO STUDIES 



constant enough to retain the name of Evermann and Cox for the western sub- 

 species. 



This little fish spawns in May and June and at this season the male is one of 

 the most briUiantly colored of North American fishes. Smith' who has studied the 

 spawning habits of C. erythrogaster in Michigan finds that two males with a female 

 held between them by the pearl organs on their scales form a spawning unit. 

 The eggs are laid on the gravel bottoms of shallow rapid streams. 

 TABLE II 



Cross Lake, Me. . . X X 



Valentine, Neb ... X X 



The food of this species, as shown by the contents of the alimentary canals 

 examined, consists of the brown and green diatomaceous and algal slime and 

 such other material as may be taken with this. So much green algal material 

 was contained by the specimens from West Plum Creek that the alcohol in which 

 they were preserved became bright green within a few days. Two specimens in 

 this same collection were badly infected with larval trematodes. 



Chrosomus erythrogaster and its varieties range throughout the northern 

 portion of the Mississippi Valley, east into Maine and west into Colorado. 



Colorado specimens. — University Museum: St. Vrain Creek, Longmont, October 17, 1903 

 {65 mm.), C. Juday and D. W. Spangler, No. 18; Boulder Creek, Boulder, October, 1903 (5 speci- 

 mens, 60-65 mm.),C.Judayand J. Henderson, No. 27; West Plum Creek near Castle Rock, June 8, 

 1912 (6 specimens, 50-65 mm.), A. G. Vestal and M. M. Ellis, No. 334; Boulder Creek 6 miles 

 east of Boulder, July 25, 1912 (5 specimens, 40-60 mm.), M. M. Ellis, No. 335; State Teachers' 

 College Museum: Greeley, A. E. Beardsley. 



Subfamily Pimephalinae 

 Genus PIMEPHALES Rafinesque 

 The Fat-headed Minnows 

 Pimephales Rafinesque, Ichthyologia Ohiensis, p. 52, 1820. 



Small herbivorous Cyprinids; alimentary canal more than twice the length of 

 the body; peritoneum black; premaxillaries protractile; mouth terminal; head 



■ "The Spawning Habits of Chrosomus erythrogaster Rafinesque," Bio/. Bull., Vol XIV, pp. 9-18, 1908. 



