68 THE FISHES OF OHIO. 



behind. Head slender and pointed; lower jaw strongly projecting; upper 

 jaw emarginate. Color, brilliant blue above, sides silvery with golden 

 reflections; no dark spot behind opercle. Length 15 inches. 



This is a deep water species, common in the Ohio river, and 

 it has made its way through the canals into L,ake Erie, where it 

 is now said to be common. Ohio river," seldom as far as Pitts- 

 burg," Rafinesque; "very rare, two specimens seen in Cincin- 

 nati market," Kirtland, 1838; Hamilton County, " abundant in 

 Ohio river," Henshall, 1888. 



Family: Salmonid^E. 

 Key to Genera. 



A. Mouth not deeply cleft; dentition feeble or incomplete, scales large. 



B. Lower jaw short and more or less included, cleft of mouth short. — 



COREGONUS. 



BB. I,ower jaw long, projecting beyond upper, cleft of mouth rather long.— 



Argyrosomus. 

 AA. Mouth deeply cleft; dentition strong and complete, scales small. 



C Vomer with raised crest, which is armed with strong teeth; hyoid bone with a 



broad band of strong teeth; no bright colors.— Cristivomer. 



CC Vomer without raised crest; hyoid with weak teeth or none; spotted with 

 red.— Salvelintjs. 



Genus: Coregonus. 

 Coregonus clupeiformis (Mitchill). Common Whitefish. 



Head 5; depth 3 to 4; eye 4 to 5. D, 11; A. 11; scales 8-74 to 85-9. 

 Body oblong, compressed, always elevated, especially so in adult. Head 

 comparatively small and short; the snout obliquely truncated. Gill rakers 

 numerous, long and slender. Color olivaceous above; sides white, but not 

 silvery; lower fins sometimes dusky. Length 2 feet or more. 



In Ohio the Whitefish is found only in Take Erie, where it 

 occurs in great numbers. It does not ascend streams. Recorded 

 first by Kirtland. "The most important fish of Ohio, both as to 

 quantity taken and quality as food," Jordan's Report; E. Erie, 

 Henshall, 1889; "common in the lake," McCormick, 1892; 

 " west end of Eake Erie," Kirsch, 1893. Great quantities from 

 various parts of the lake are brought into the fish houses at San- 

 dusky. 



