74 UNIVERSITY OF COLORADO STUDIES 



b. Vomer flat; American species spotted with black but not with red, pink or gray; introduced 

 European species spotted with black and scarlet, the scarlet spots being more or less ocellated 

 with white, adipose fin tipped with bright orange-yellow, general color above brownish. 



Salmo (Artedi) Linnaeus, p. 75 

 bb. Vomer boat-shaped; species spotted with red, pink or gray, but without ocellated scarlet 

 spots. 

 c. Vomer without a raised crest; species much spotted with bright red; anterior margins 



of lower fins white Salvelinus Richardson, p. 84 



cc. Vomer with a raised crest extending posteriorly from the head of the bone; species 

 spotted or mottled with gray or rarely pale grayish pink, but without bright red spots. 



Cristivomer Jordan and Gill, p. 85 



Subfamily Coregoninae 



Genus COREGONUS (Artedi) Linnaeus 



The Whitefish 



Coregonus Artedi, Genera Piscium, p. 9, 1738. 



Coregoni Linnaeus, Systema Naturae, ed. X, p. 310, 1758. 



Body compressed; head rather short and somewhat conical; mouth small, 

 angle of the mouth barely if at all reaching the level of the anterior portion of the 

 eye; scales not extremely small, but rather prominent. 



Species of this genus are found in both the old and new worlds and most of 

 them are food fishes of value. A single species is fairly abundant in northwestern 

 Colorado. 



Coregonus williamsoni Girard 



Williamson's Whitefish, Rocky Mountain Whitefish 



Coregonus williamsoni Girard, Proc. Acad. Nat. Sci. Phila., p. 136, 1856 (Deschutes River, 

 Oregon); Evermann and Smith, Rept. U.S. Com. Fisheries Jor 18Q3-Q4, p. 293, 1896 (Meeker, 

 Colorado) . 



Body compressed and somewhat elongate, its depth 4 to 5 in the length; 

 head rather short and conical, its dorsal profile sloping rather abruptly, ventral 

 profile almost straight, length of the head about equal to or a little less than the 

 greatest depth of the body; eye large, nearer to the tip of the snout than to the 

 gill opening, situated in the upper half of the head, diameter of the eye less than 

 the length of the snout, 4 or more in the head; snout rather short and blunt in 

 females and young, in breeding males somewhat produced and upturned at the 

 tip; mouth small, sUghtly ventral, angle of the mouth barely reaching the level 

 of the anterior margin of the orbit; lower jaw shorter than the upper, by which 

 it is partly included; dorsal fimi rather short and high, length of its longest ray 

 almost or just equalling the length of the base of the dorsal, which is about i . 5 

 in the head; dorsal rays 12 to 14, base of the first ray of the dorsal about midway 

 between the tip of the extended pectoral and the origin of the ventrals; pectorals 

 short, separated from the ventrals by about their own length; ventrals much the 

 same size as the pectorals, origin of the ventrals on a level with about the tenth 



