SALMONID^E. CV. 259 



variations due to age, sex and food are very great, and 

 have led to the establishment of a great number of nomi- 

 nal species in all the leading genera, particularly in 

 Salmo. 



* Jaws with evident teeth. 



f Dorsal moderate of less than 20 rays; teeth strong, on jaws, 



vomer and tongue. 



\ Scales small ; partly imbedded in the skin ; lat. 1. 100 or 

 more SALMO, 1. 



\\ Scales moderate, deciduous, not imbedded ; lat. 1. 60 to 70. 



OSMERUS, 2. 

 ft Dorsal veiy high of 20 or more rays ; teeth small. 



THYMALLUS, 3. 

 ** Teeth wanting or reduced to slight roughnesses ; scales rather 



large, loose. 



a. Lower jaw longer than upper, or if not, body slender, sub- 

 fusiform ARGYROSOMUS, 4. 



CM. Upper jaw notably longest; body more or less elevated. 



COREGONUS, 5. 



/. SALMO, Linnaeus. SALMONS. 



> SalmO) Fario, Salar^ Trutta, Umbla^ Hucho, Sal- 

 velini) etc., of Authors. 



* Anadromous species, running up from the sea into fresh water 



to spawn ; the young remaining there for a time, then return- 

 ing to the sea where they remain except during the season 

 of reproduction; upper jaw in males moderately if at all 

 hooked. (Salmo.) 



1. 5. salar, L. GREAT SEA SALMON. No red spots; 

 young (Parr. Smolt) with dusky cross bars; males in 

 the spawning season with the lower jaw strongly re- 

 curved and hooked; body covered with black and red 

 patches; others silvery, with small black dots; eleven or 

 twelve scales in a transverse series from behind the adi- 



