SALMO SALAR. 267 



the caudal fin in relation to size, age, and reproductive condition ; 6, size of 

 the pectoral fins ; 7, size of the scales, as shown in the number of rows above 

 the lateral line ; 8, number of the vertebrae ; and 9, number of pyloric append- 

 ages to the intestine. All these characters, however, are more or less inconstant. 

 The genus Salmo is divided into two sub-generic groups Salmones and 

 Salvelini. The former have the teeth not only on the front of the vomer 

 but along its length, though the hinder teeth in some species are lost with age. 

 These fishes are usually known as Salmon and Trout. The Salvelini have 

 teeth on the front of the vomer only, and are known as Charr. Both groups 

 have representatives in many northern countries, peculiar species being found 

 in the British Islands, France, the Alpine region of Europe, Hungary, 

 Algeria, Italy, Russia, and Tartary, the Scandinavian peninsula, and Finland ; 

 while many species are common to Northern Asia and North America, and 

 others are limited to the Rocky Mountains, to Greenland, and Labrador. 



Salmo salar LINN^US). The Salmon. 



22 26 



D. 14, A. 11, P. 14, V. 9. Scales : lat. line 120130, trans. to - 



19 22 



The form of the Salmon is rather elongated. The length of the head is 

 nearly equal to the greatest height of body; the snout is pointed. The 

 ventral contour is very much arched, while the dorsal profile is flatter. The 



Fig. 145. SALMO SALAR (LINN.EUS). 



body is deepest under the dorsal fin, and five and a half to five and three- 

 quarter times as long as high. The greatest thickness of the body is about 

 one half of the height ; the diameter of the eye does not exceed the length of 

 the head. The length of the snout is twice the orbital diameter, and the 

 nares are midway in the length of the snout. The breadth of the inter-orbital 

 frontal space is two and a half times the width of the eye. There is a 

 half -moon-shaped furrow in front of the eye (Fig. 145) . 



