



_J 



304 FISHES OF THE FIRTH OF FORTH. 



tory species, since no instance has been recorded of its cap- 

 ture in the sea. Nor does it appear to me to be so com- 

 mon a fish as is generally considered. Its habits require 

 further investigation. 



Salmo fario.* — The Common Trout. 



Specific Characters. — Vomerine teeth extending the whole way ; 

 middle ray of the tail more than half the length of the longest ray in 

 the same fin ; body marked more or less with red spots. (See Plate 

 XXX.) 



Description. — From a specimen one foot in length. Head one-fifth 

 of the whole length, caudal fin included ; depth under the dorsal 

 less than the length of the head. Colour of the back dusky inclin- 

 ing to olive, sides lighter ; belly yellowish ; sides above the lateral 

 line marked with about fifty dark round spots ; below the line about 

 ten, surrounded by a pale circle ; lateral line with eight red spots, 

 which are more conspicuous on the caudal half of the body ; pecto- 

 rals yellowish, the remaining fins dusky ; dorsal spotted, with the 

 summits of the second, third, fourth, and fifth rays white, and an 

 oblique black band beneath ; the first ray of the anal fin white, with 

 the four following ones, marked like those of the dorsal ; gill-cover 

 marked with five or six dark round spots (colour and spots very va- 

 riable). First dorsal fin placed half-way between the point of the 

 snout and a little beyond the fleshy portion of the tail ; the first two 

 rays simple (there are generally three simple rays in the trout and 

 salmon, but the first being so very small is not taken into considera- 

 tion), the rest branched ; the fourth the longest, equalling the length 

 of the long ray of the caudal fin ; the last considerably more than 

 half the length of the fourth ; the eighth as long as the base of the 

 fin. Adipose fin in a line immediately over the base of the last ray 

 of the anal, and nearer the last ray of the dorsal than to the tip of 

 the tail ; caudal fin nearly even at the end (in young specimens more 

 or less forked) ; the fourth ray of the anal fin the longest, nearly twice 

 the length of the base of the fin ; the last ray half the length of the fifth ; 

 all the rays branch except the two first which are simple ; fourth ray 

 of the ventral fin the longest, equalling the length of the seventh ray 

 of the dorsal; base of the ventrals in a line under the last ray but 

 five of the dorsal. Pectorals rounded, the fourth ray the longest, a 

 very little longer than the long ray of the caudal fin ; the last ray 

 but one half the length of the third. Basal line of the operculum ob- 

 lique ; subopcrculum slightly produced behind (in some individuals 



* Salmo fario Auctorum. 



