58 CHECK LIST OF THE 



bone broad, rather short, its supplementary piece ovate. Mandible reach- 

 ing middle of eye. Tongue with about three series of small teeth. Supra- 

 orbital bone narrow. Dorsal fin high in front, the last rays short. 



D., II or 12; A., II or 12; Scales, 10-71 to 76-g. 



Colour, bluish black above ; silvery below ; scales with dark punctula- 

 tions on the edges; fins all dusky, pectorals and ventrals pale at the base. 



Length, twenty-one inches. 



A very variable species, by some authorities considered indistinguish- 

 able from C. clupeiformis. 



Generally distributed in cold, clear lakes and large streams, especially 

 northward. 



Genus ARGYROSOMUS. (Ciscoes.) 



This genus is very close to Coregonus, from which it differs in the 

 larger mouth and more produced jaws, the premaxillaries being placed 

 nearly horizontally, and the lower jaw decidedly projecting beyond them. 

 Gill rakers very long and slender, about thirty on lower limb ; vertebrae, 

 fifty-fi\'e. These characters are associated with the geater voracitv. and 

 in general greater activity of the species of Argyrosomus. 



Subgenus ARGYROSOMUS. 



(66) Cisco. Lake Herring. 



(Argyrosomus artedi.) 



Body long, slender, and somewhat compressed ; dorsal and ventral 

 outlines but little arched; head pointed; mouth large, jaws subequal or 

 the lower somewhat projecting; maxillary long, usually reaching to ver- 

 tical of pupil. Caudal peduncle slender, but not much compressed; dorsal 

 fin small ; adipose fin slender, its width one-half its height. 



D., II ; A., 10 (counting only divided rays in dorsal and anal); V., 10. 



Colour, above dull bluish green ; lower part of sides and below silvery 

 white. Dorsal fin sometimes black tipped; caudal dusky at tip; anal and 

 ventrals pure white. 



This species attains a length of about twelve inches and a weight of 

 about one pound. Larger specimens have been recorded, but they are 

 exceptional. 



The Cisco ranges through the Great Lakes generally, but is most 

 abundant in Lake Erie ; it was formerly common in Lake Ontario. Of late 

 years, however, it has not been taken there in any quantity. Its spawning 

 season is in November and early December. 



