1. SALMO. 21 



Description of a young Male Salmon {Parr) from the Kidder {a roch/ 



mountain-stream jolnlny the River Tyne, in Northumberland), 



with the testicles fully developed, 6|- inches long. 



Total length g i 



Greatest depth of the body \j_ 



Length of the head ' ' . _ 23** 



Girth of the biggest part of the body .. . 31 



Least depth of the tail %_^ 



Gii-th of the narrowest part of the tail '. . '. IJ " 



Distance between the end of the snout and the eye . . t 



Length of the maxillary bone JL. 



Distance between the eye and the angle of the prse- ' ** 



operculum 3 



Greatest width of the operculum i 



Greatest depth of the operculum X 



Distance between the occiput and the origin of the ^"^ 



dorsal fin jg 



Distance between the end of the dorsal and the root of '^ 



the caudal fin 2J- 



Length of the base of the dorsal ' ' A** 



Greatest height of the dorsal 1 



Length of the pectoral 11 



Distance between the root of the pectoral and the root ^ 



of the ventral ]^5 



Length of the ventral fin ' | i 



Distance between the root of the ventral and the origin ** 



of the anal \ 



Length of the anal _a^ 



Greatest depth of the anal i*" 



Length of the longest caudal ray 1 i. 



Length of the middle caudal ray JL. 



The greatest depth of the body is below the origin of the dorsal 

 fin, and contained thrice and two-thirds in the total length (without 

 caudal), the length of the head being one-fourth of it. The snout 

 is obtuse, not longer than the diameter of the eye, which is one- 

 fourth of the length of the head ; the dentigerous margin of the 

 intermaxillary bones is on the same level with the lower margin of 

 the orbit ; the lower jaw has no trace of a hook, is obtusely rounded 

 111 front, and received within the u^jper jaw ; the maxillary bone is 

 longer than the snout, chlated behind as in a river-trout, the width 

 of its broadest portion being one-half of the diameter of the eye ; it 

 extends backwards to below the middle of the orbit. The dentition 

 is perfect, and there is the same relative difference in the size of 

 the teeth as in adult specimens ; the teeth of the intermaxillary 

 bones form a curved, uninternipted, transverse series : those on the 

 vomer are small, in a single series, extending further backwards 

 than the palatine teeth, the teeth being alternately bent towards the 



