60 CHECK LIST OF THE 



Colour, dark bluish above ; sides silvery, with dark punctulations ; 

 fins all blue-black. 



This species may be readily known by its black fins. 



During the last few years the Black-fin has been occasionally reported 

 from Lake Superior ; its centre of abundance, however, appears to be 

 Lake Michigan and the deep water lakes of Minnesota and Wisconsin. 



In its habits it resembles the other members of the group, swimming 

 in shoals and depositing its spawn upon rocky bottom in November and 

 December. 



It reaches a length of eighteen to twenty inches and is considered a 

 good food fish. 



SUBGENUS ALLOSOMUS. 



(69) Tullibee. Mongrel Whitefish. 



(Argyrosomus tullibee.) 



Body short and deep compressed, the dorsal and ventral outlines 

 similarly curved ; head small, conic and compressed ; mouth large, lower 

 jaw slightly projecting. Scales larger on front of body than on caudal 

 peduncle; free margins of the scales less convex than in other species, 

 often emarginate, especially on anterior part of body. Lateral line straight 

 and in a line with upper rim of orbit ; tongue with a patch of fine teeth 

 near the tip ; gill rakers numerous, long and slender. 



D., 10 to 12 ; A., ii or 12. 



Scales on lateral line, 68 to 74, eight or nine rows above and seven 

 or eight below. 



Colour, iridescent bluish above, sides and under parts silvery; old 

 individuals darker above, with some golden reflections on side ; fins more 

 or less evidently black tipped ; upper edge of pectoral margined with black. 



From all other Whitefishes the Tullibee may be distinguished by the 

 short steep body and the closely imbricated scales. It attains a length of 

 eighteen or twenty inches and a weight of about three and a half pounds. 

 As a food fish it is highly esteemed, but its commercial importance is as 

 yet limited. 



This species is usually called the Tullibee, but it is sometimes styled 

 the "Mongrel Whitefish" on the erroneous supposition that it is a cross 

 between the Whitefish and the Lake Herring. 



In the Great Lakes it is not at all common, occurring in limited num- 

 bers in Lakes Erie and Superior only, but in the Lake of the Woods and 

 through Manitoba and Assiniboia it is abundant. 



Mr. F. C. Gilchrist, in describing the habits of this fish in Western 

 Canada, says: "In September they will be found gradually nearing the 

 shoal water, feeding heavily, plump with fat and the now swelling ovaries. 

 Later on they appear to eat little or nothing and devote all their time to 

 playing until about the 25th of October, when they settle down to the 



