48 UNIVERSITY OF COLORADO STUDIES 



Richardsonius evermanni (Juday) 

 Evermann's Dace 



Leuciscus evermanni Jnda,y, Univ. Colo. Studies, Vol. 11, p. 113, 1903 (Boulder Creek, Boulder); 

 Idem, Bull. U.S. Fish Com. for 1904, p. 226, 1905 (Boulder Creek, Boulder). 



Body elongate, somewhat compressed; head about 3.75, depth about 4.5 

 in the length to the base of the caudal; eye about 4. 5 in the head, a little more 

 than I in the snout, and i . 5 in the interorbital distance; mouth large, angle of the 

 mouth almost reaching the level of the anterior margin of the eye ; base of the first 

 ray of the dorsal fin on a level with the base of the ventrals, dorsal rays 8 ; pecto- 

 rals short, not reaching the ventrals by the diameter of the eye; ventrals passing 

 the anal opening but scarcely reaching the anal fin; anal fin of 8 rays; caudal 

 peduncle rather broad, about 2. 5 in the head; scales 8 or 9, 45-47, 5, 25 in the pre- 

 dorsal series; lateral line interrupted, decurved in the pectoral region. Dusky 

 above, lighter below; a dark mid-dorsal stripe and a dusky lateral band; scales 

 outlined with dusky, giving the body above the lateral line somewhat reticulated 

 pattern. 



This species is known at present from three specimens coUected by Juday in 

 1903 in Boulder Creek near Boulder. The above description was made from 

 Cotjrpe No. I, University of Colorado Museum, No. 14. 



Genus NOTROPIS Rafinesque 

 The Shiners 

 Notropis Rafinesque, Amer. Monthly Magazine, Vol. II, p. 204, 1818. 



Small compressed or elongate, carnivorous Cyprinids, the larger species rather 

 deep; alimentary canal short ; mouth terminal, usually not very large; no maxil- 

 lary barbel; pharyngeal teeth (see Richardsonius) in one or two rows, 0-4-4-0, 

 1-4-4-1 or 2-4-4-2 ; species very numerous and variable, distributed throughout 

 the United States and lower Canada east of the Rocky Mountains. The follow- 

 ing key will serve to separate the Colorado species of this genus. 



Key to Colorado Species of Notropis 



a. With dusky lateral band or stripe, or at least dusky lateral clouds; sides more or less silvery- 

 b. Lateral stripe prominent, extending across the side of the head through the eye to the tip 



of the snout N. cayuga Meek 



bb. Lateral stripe not extending across the head to the tip of the head, often rather indistinct 

 and much interrupted. 

 c. Anal rays 7 or 8; body elongate and not deep. 



d. Entire predorsal region usually scaleless, or scales if present in this region small, 



crowded and wanting near the head N. piptolepis (Cope) 



dd. Predorsal region regularly and evenly scaled; 14 to 16 scales of rather uniform size, 



in front of the dorsal fin N. scylla (Cope) 



cc. Anal rays 9 or 10. 



e. s to 7 scales between the base of the first ray of the dorsal fin and the lateral line. 



