46. SALMONIDiE — COREGOXUS. 297 



jiciier.illy supposed. The species arc liiglily valued for food, the flesh 

 bciug generally i)alc and of flue flavor. TUe coloratiou is very uui- 

 form ; bluish olivaceous above; the sides and below silvery, {y-^rn^ 

 the temples; ydi-jo^^ angle.) 



This genus uiiiy be subdivided as follows: 



* Lower jaw included ; preiiiaxillaries broad, i)laced verfieally or the lower edge turned 



inward. 



tGill-rakers sliort, thiekisli, few iu nuniT)er; xircorbital broad, wider than pupil ; 



maxillary sliort and rather broad, not reaching to the lino of the eye; the 



small supplementary bone mostly narrow and sharply elliptical ; mouth very 



small (PitosoPiUM Milner) couesi, wilUamsoni, quadrilateraUs, Icennicolti. 



ft Gill-rakers numerous, long, and slender; preorbital long and narrow; maxillary 

 comparativelj' long, the supplemental bone ovate. (Coregoxus.) 



t Tongue toothless, or nearly so; back elevated dniyelfonnis. 



It Tongue with about three series of small teeth; body elongate, con)pressed. 



lahradoricns. 



XX\ Tongue nearly toothless; back not elevated hoyi. 



** Lower jaw projecting; i)remaxillaries narrow, placed more or less horizontally. 



$ Body elongate, snbfusiform; scales small, uniform, convex behind (AuGYlto- 



SOMCS Agassiz) merlci, artcdi, viijripinnis. 



§!JBody short, deep, compressed, shad-like; curve of the back similar to that 

 of the belly; vseales large, larger forwards, rather closely imbricated, the 

 posterior margin little convex (Allosomus Jordan) tuUibce. 



•Lower jaw included; premaxillaries broad, placed vertically or turned inwai-d. 



tGill-rakers short, thickish, few in number; preorbital broad, wider than pupil; 

 maxillary short and rather broad, not reaching to the line of the eye ; the 

 snuill supidementaiy bone mostly narrow and sharply ellii)tical; mouth very 

 small. {I'rosopium* JMilner.) 



486. C. COMCSi Miluer. — Chief MoKiilain TThHc-fiHli. 



Head narrowed anteriorly, the snout prolonged, pig-like, protruding 

 beyond the mouth. Maxillary 4 iu head, barely reaching eye. Sub- 

 orbital and supraorbital wider than in the other species. Depth 41 in 

 length; length of head about the same; body therefore elongate, not 

 elevated nor much comi^ressed. D. 12; A. 10; scales 8-8S-7. Chief 

 Mountain Lake, Montana, a tributary of the Saskatchawau. Verj' close 

 to the next, if really different; the head and mouth larger in the single 

 specimen known. 



(Milner, Eei)t. U. S. Fish Com. 1872-7.3, 83 : Prosoinum couesi Miluer, in Jordan, Man. 

 Vert. ed. 2, 3G2.) 



487. C '\Vd3aa:iDnsOiai Girard. — Boclcxj Mountain White-fish. 



Body oblong, rather deeper than in C. quadrilateraUs^ but little com- 

 pressed. Head shortish, conic, the proflle more abruptly decurved 

 than in the others. Snout compressed and somewhat pointed at tip, 

 •which is eutirel^y below the level cf the eye. INIaxillary short and very 



* Miluer, in Jordan Man. Vert. ed. 2, 331: type C. quadrilateral is Rich. {Tzpoauirdov, 

 a mask; from the broad preorbital.) 



