44 PBELIMINAEY EEPOET 



KEY TO THE GENERA OF SALMONIDJJ. 



A. Mouth small; maxillary bones broad; teeth none, "or very few; 

 supplemental maxillary bone present. 

 B. Lower jaw short and generally not longer than the upper; 

 mouth not widely cleft; premaxillary bones broad, their 



cutting edges nearly vertical Coregonus, 44 



BB. Lower jaw long, projecting beyond the upper; mouth widely 

 cleft; premaxillaries with their cutting edges nearly hori- 

 zontal Argyrosomus, 45 



AA. Month large; maxillary bones narrow; teeth present, strong and 

 complete; anal fin with 9 to 12 rays; scales very small. 

 B. No bright colors, spotted with gray; vomer with a toothed 



crest or ridge Cristivomer, 47 



BB. Body dotted with red spots, these fading to white in alcohol; 

 lower fins edged with red; no crest or ridge on the vomer. 



Salvelinus, 47 



Genus COREGONUS fArtedi) Linnaeus. 



Coregonus clupeiformis (Mitchill). Common Whitefish. 



Color white but not silvery, darker above. Body much com- 

 pressed, long; back somewhat elevated. Head small; snout short 

 and blunt; maxillary bone contained about 4 times in the head, its 

 tip reaching back of the front of the eye socket. Gdll rakers ^ as 

 long as the width of the eye, 10+17 to 19. Head contained 5 times 

 in the length. Depth 3 to 4. Eye 4 to 5 in the head. Dorsal fln 

 with 11 rays. Anal 11. Scales 8-74-9. Length 2 feet. 



This is our common white-fish of Lake Superior and possibly 

 it may be found in some of the smaller lakes. Many people report 

 a white-fish from the smaller lakes, but no specimens have been 

 taken in the various collections. It remains to be determined 

 whether the fishes reported are this or Argyrosomus nigripermis^ 

 It was described as C. sapindissimus Agassiz, Lake Superior, 344, 

 1850, from Lake Superior, also as O. latior Agassiz from the same 

 place in the same work, page 348. It is taken in abundance at all 

 the fishing stations on Lake Superior during the fishing seasons. 



