1. SALMO. 19 



operculum and suboperculum is subsemicircular ; when we fix three 

 points on this curved line, viz. the upper end of the gill-opening, 

 the junction of the operculum and suboperculum, and the lower end 

 of the suboperculum, and when we connect these three points by 

 two cords, the two straight lines are equal. 



The distance of the origin of the dorsal fin from the occiput is a 

 little less than its distance from the adipose fin. It is nearly as long 

 as high, and composed of thii'teen rays, which are enveloped in a 

 thick callous skin. The anal fin is higher than long, and composed 

 of eleven rays, which have been more or less injured through the 

 exertions of the fish. Pectoral fin nearly as long as the head with- 

 out snout, considerably longer than the ventral, the length of which 

 is three-fiifths of the distance of its root from the vent. Posterior 

 margin of the caudal truncate. 



There are 120 transverse series of scales ; the transverse series 

 descending obliquely backwards from the origin of the dorsal fin to 

 the lateral Hne contains twenty-six scales ; and there are twenty-two 

 longitudinal series between the lateral line and the base of the ven- 

 tral fin. 



Upper parts blackish dark green ; sides more whitish ; beUy 

 reddish. The supraorbital region, the operculum, and the upper 

 parts of the body are marked with black spots, broadly edged with 

 pearl-colour ; some on the body are half as large as the eye, but 

 they are not very numerous. There arc a number of purple vermi- 

 ciilated lines between the black spots ; and similar markings, but of 

 a blood-red colour, occupy the base of the caudal and some parts of 

 the belly. The outer half of the caudal is greenish black. 



Description of a Male specimen ccmglit in the Firth of Forth, 

 22 inches long. 



inches 



Total length 22 



Greatest depth of the body 3| 



Length of the head 4 



Girth of the biggest part of the body 10 



Least depth of the tail .' 1-| 



Girth of the narrowcbt part of the tail 4^ 



Distance between the end of the snout and the eye . . 1^^ 



Length of the maxillary bone li 



Distance between the eye and the angle of the prae- 



operculum 1| 



Greatest width of the operculum 1 



Greatest depth of the operculum li- 



Distance between the occiput and the origin of tho 



dorsal fin Gi 



Distance between the end of the dorsal and the root 



of the caudal fin 7 L 



Length of the base of the doi-sal 2^ 



c2 



