THE SALMON FAMILY. 6/ 



the hypothesis of recent adaptation of the sal- 

 mon to lake-hfe. We have, therefore, on our 

 Atlantic coast but one species of salmon, Salmo 

 salar. Dr. Francis Day, who has very thoroughly 

 studied these fishes, takes, in his memoir on '' The 

 Fishes of Great Britain and Ireland," and in other 

 papers, a similar view in regard to the European 

 species. Omitting the species with permanent 

 teeth on the shaft of the vomer (sub-genus Salar), 

 he finds among the salmon proper only two 

 species, Salmo salar and Salmo trutta. The latter 

 species, the sea-trout or salmon-trout of England, 

 is similar to the salmon in many respects, but has 

 rather smaller scales, there being fourteen in an 

 oblique series between the adipose fin and the 

 lateral line. It is not so strong a fish as the sal- 

 mon, nor does it reach so large a size. Although 

 naturally anadromous, like the true salmon, land- 

 locked forms of the salmon-trout are not un- 

 common. These have been usually regarded as 

 different species, while aberrant or intermediate 

 individuals are usually regarded as hybrids. 



The present writer has examined many thou- 

 sands of American Salmonidce, both of Oncorhyn- 

 chus and Salmo, While many variations have 

 come to his attention, and he has been compelled 

 more than once to modify his views as to specific 

 distinctions, he has never yet seen an individual 

 which he had the slightest reason to regard as a 

 " hybrid." It is evident that in America but few 

 species of salmonoids exist, and that these are 

 subject to many variations. It is certainly illogical 

 to conclude that every specimen which does not 



