38 UNIVERSITY OF COLORADO STUDIES 



The Stone-roller feeds upon the brown and green slime found on stones and 

 debris in the stream, in this way taking diatoms, algae, small insect larvae and 

 small snaUs. Several specimens from Wray were found to have the alimentary 

 tract filled with sandy mud in which almost nothing of food value could be found. 

 The larger specimens of this fish were taken in the deeper parts of small streams, 

 and the young from the more shallow weedy portions near shore. Several indi- 

 viduals were collected in the quiet water back of a beaver dam on West Plum 

 Creek. As a food fish the Stone-roller has httle value, although the larger indi- 

 viduals are often eaten. The young make very good live bait for bass and both 

 old and young live very well in large aquaria and small artificial ponds. 



Campostoma anomalum ranges throughout the Mississippi Valley west to the 

 Rocky Mountains. It spawns in the early spring. 



Colorado specimens. — University Museum: Boulder Creek, Boulder, October, 1903 (7 speci- 

 mens, 75-125 mm.), C. Juday and J. Henderson, No. 6; Boulder Creek east of Boulder, 

 May, 190Q (12 specimens, 95-125 mm.), David Rusk and Donald Kloke, No. 31; West 

 Plum Creek near Castle Rock, June 8, 1912 (12 specimens, 40-150 mm.), A. G. Vestal and M. M. 

 Ellis, No. 329; South Platte River, Julesburg, July 19, 1912 (72 specimens, 50-120 mm.), J. 

 Henderson and M. M. Ellis, No. 330; Lodgepole Creek near Ovid, July 20, 1912 (4 specimens, 

 75-120 mm.), J. Henderson and M. M. Ellis, No. 331; Boulder Creek 6 miles east of Boulder, 

 July 25, 1912 (4 specimens, 50-85 mm.), M. M. Ellis, No. 332; Republican River, Wray, Octo- 

 ber 26, 191 2 (63 specimens, 45-105 mm.), A. G. Vestal and M. M. Ellis, No. m. Reported by 

 A. E. Beardsley as common at Greeley until killed out by the refuse from the sugar factories. 



Subfamily Chrosominae 

 Genus CHROSOMUS Rafinesque 

 The Red-bellied Dace 

 Chrosomus Rafinesque, Ichthyologia Okiensis, p. 47, 1820. 



Small herbivorous Cyprinids; alimentary canal about twice as long as the 

 body; peritoneum black; no maxillary barbel; mouth terminal; lateral line 

 short and interrupted or wanting; scales small, with apical, lateral and basal radii, 

 65-90 in the lateral line series. Species of the United States and lower Canada 

 east of the Rocky Motmtains. One species known from Colorado. 



Chrosomus erythrogaster Rafinesque 

 Red-bellied Dace 



Chrosomus erythrogaster Rafinesque, Ichthyologia Ohiensis, p. 47, 1820 (Ohio River). 

 Represented in Colorado by the western subspecies. 



Chrosomus erythrogaster dakotensis (Evermann and Cox) 

 Western Red-bellied Dace (Fig. 12) 



Chrosomus dakotensis Evermann and Cox, Rept. U.S. Com. Fisheries for 1894, pp. 3Q5-396, 

 1896 (Crow Creek, Chamberlain, South Dakota). 



Chrosomus erythrogaster Rafinesque — JtiDAY, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder 

 and Longmont); Jctdav, Bull. U.S. Fish Com. for IQ04, p. 226, 1905 (Boulder; Longmont). 



