302 



TIIK FBESH-WATEH FISIIKS OF Kl'ROl'F. 



As compared with the May Trout, the whole form is rather plumper aud 

 thicker, hut the proportions and measurements of length of head and height of 

 body are much the same, and there is no important difference in size and 

 number of scales, or position and form of the fins. The diameter of the eye is 

 also one-sixth of the length of the head, but its hinder border is farther from 

 the edge of the pre-operculum, and the maxillary bone extends farther back. 

 The teeth on the body of the vomer form a single straight row (Fig. 155) ; 

 but Heckel and Kner remark that so long as the skin of the palate is not 

 removed, the vomerine teeth appear to form a double row, since their points 

 diverge alternately to the right and to the left. There are three transverse 



Fig. 155. FRONT VIEW 



OF VOMER OF SALMO 

 MARSIGHI. 



Fig. 154. SALMO MAUSIGLII (HKCKEI,). 



teeth. As in the May Trout, the branchiostegal rays are ten on the right side, 

 eleven on the left. The rake-teeth on all the branchial arches are shorter 

 and less numerous, remarkably short on the last arch, and from seven to nine 

 in number, often near together in pairs, but sometimes 

 at equal distances from each other. The pre-operculum 

 is crescent-shaped, with a very indistinct lower limb ; 

 the posterior opercular margin is rather angular. The 

 snout is of moderate length. 



The dorsal profile is more regularly arched than the ventral contour. The 

 scales are always firmly adherent. The number of pyloric appendages is from 

 eightv to a hundred. Those in the first row are not shorter than the others. 



The colour changes so quickly after death that the ground-colour is then 

 scarcely to be recognised ; but in life the upper part of the head and the back 

 are dark-green, only comparable to the colour of the water of the lakes in 

 which the fish lives. This beautiful tint gets paler towards the lateral line, and 

 is in contrast to the pale blue of the May Trout. After death it becomes opaque 

 brown. The sides are silvery, with a little violet ; the throat and belly 

 have the whiteness of pure silver. The upper part of the operculum is green, 



