HIGH SCHOOL ZOOLOGY. 



59 



which ascends rivers on both sides of the Atlantic for the pui'- 

 pose of spawning, and is consequently described as migratory 

 or anadromous, althongh it is able to live also permanently in 

 fresh water. Such " land-locked " salmon used to be abundant 

 in Lake Ontario. 



Fig. 24.— The Atlantic Salmon. Salnw solar. ^. 

 (U. S. F. C). 



The Pacific salmon, which are canned in enormous quantities in Brit- 

 ish Columbia, belong to an allied genus Ondiorhjoiclius. 



11. Our common Luke Trout and Brook Trout belong to a 

 "enus Salvelinus differing from Sal mo in the absence of teeth 

 on the vomer ; the former (^S. namaycush) attains a large size, 

 and is abundant in the larger lakes, the latter {S. /ontirudis) is 

 found in ponds and streams, and is well known by its brilliant 

 colouring, except in those individuals which have access to the 

 sea, and which replace the red spots and dark bars by an uni- 

 form silvery dress. Hardly less important are the common 

 Lake sjiecies of White fish {Coregonus clupeiformis) and Lake 

 Herring or Ciscoes {G. artedi) (Fig. 25) which difier from the 



Fig. 25.— The Cisco, or Lake Herring. 

 (U. S. F. C.) 



Corego-nus artedi. 



