Fishes of the Western North Atlantic 459 



I b. Lower margin of sides of upper jaw (maxillary bone) strongly convex in outline 

 (Fig. 119). Brachymystax Giinther i860. 



Rivers of Siberia. 



Genus Sahno Linnaeus 1758 

 Salmon, Trouts 



Salmo Linnaeus, Syst. Nat., J, 1758: 308; type species, Salmo W<?r Linnaeus, established by Jordan and Gilbert, 

 Bull. U.S. nat. Mus., 16, 1882: 309. European Ocean. 



Generic Synonyms: 



Trittta Geoffroy, E. L., Descr. 719 Plantes, 134 Animaux., Paris, 1767: 719. 



Fario Cuvier and Valenciennes, Hist. Nat. Poiss., 21, 1848: 227; argenteus equals trtitta. 



Salar Cuvier and Valenciennes, Hist. Nat. Poiss., 21, 1848: 294; ausonii equals /^n'o. 



Species. Salmo., the type genus of the family, contains the species originally named 

 THE Salmon {S. salar) and the Trout {S. truttd). In addition to the Trout, other black- 

 spotted trout closely related to it are included. These occur chiefly in Europe and 

 North America; a few are found in areas that may be regarded as extensions of the 

 main centers of distribution. 



Some isolated landlocked populations have diverged so far from the presumed 

 parent stocks as to constitute distinct species. In the case of others, the question of 

 their taxonomic status is still a matter of doubt. This has led to uncertainty as to how 

 many species should be recognized. Three species fall within the scope of this book: 

 S. salar, the Atlantic Salmon, which is anadromous and spawns in fresh water (see 

 also Freshwater Populations, p. 491); S.trutta, the European trout, an introduced 

 species that is anadromous in Newfoundland and is called the brown trout in America 

 (p. 498); and S.gairdneri, the rainbow trout, which is indigenous in northwestern 

 America but which has been widely introduced and is well established in the north- 

 eastern United States and eastern Canada, occurring mostly in fresh water but being 

 anadromous locally (p. 499). 



Key to Species of the Western North Atlantic 



I a. Anal usually with 9 fully developed rays; caudal usually unspotted. 



2a. Vomerine teeth little developed, those on shaft few and deciduous; scales 

 from adipose fin to lateral line, 10—13; maxillary extending to below rear 

 edge of pupil at length of 150 mm, never far behind in large adults; caudal 

 weakly concave in adults; black spots on body small, without halos. 



salar Linnaeus 1758, p. 460. 

 2 b. Vomerine teeth well developed, those on shaft of bone numerous and per- 



