1. SALMO. 41 



vomerine teeth only three remain. The head of the vomer is sub- 

 triangular, rather broader than long ; the body of this bone has a 

 slight transverse ridge where it joins the head, and is provided with 

 a sharp, prominent longitudinal ridge bearing the teeth. One of 

 the three teeth occupies the transverse ridge, the two others the 

 front part ^f the longitudinal one. The distance of the nostrils 

 irom the orbit is about two-thirds of the diameter of the latter ; the 

 interorbital space is very convex, the orbit being far below the upper 

 profile of the head; the width of the interorbital space is about 

 four-fifths the length of the maxillary bone, and two-thirds that of 

 the space between the pupil and the angle of the prscoperculum. 

 The posterior margin of the operculum is straight, but inclining 

 backwards considerably as it descends ; it is placed at right angles 

 to its lower margin, the angle of the suboperculum being much 

 rounded ; a line drawn from the upper end of the giU-opcning to 

 the point of junction of the operculum and subojierculum is somewhat 

 less than twice the length of one from that point to the lower end 

 of the suboperculum. 



The distance of the origin of the dorsal fin from the occiput, if 

 carried backwards from behind that fin, reaches to almost midway 

 between the adipose and the root of the caudal. The dorsal fin is 

 rather longer than high, and composed of fourteen rays, the tkree 

 anterior ones being rudimentary and enveloped in skin, whilst the 

 fourth is simple but much shorter than the fifth and sixth, which 

 are branched and the longest of the fin. The anal fin is higher 

 than long, and composed of eleven rays, of which the first and second 

 are rudimentary and enveloped in the skin, the third simple, while 

 the fourth and fifth are branched, equal in length, and the longest 

 of the fin ; the last ray is split to its base. Pectoral fin nearly as 

 long as the postorbital portion of the head : ventral fin shorter, its 

 length being one-half the distance of its root from the vent ; its outer 

 ray is in the vertical from the middle of the dorsal fin. Posterior 

 margin of the caudal fin truncated. 



There are 125 transverse series of scales, counted immediately 

 above the lateral line ; the transverse series descending obliquely 

 backwards from the origin of the dorsal fin to the lateral line contains 

 twenty-seven or twenty-eight scales, and there are twenty longi- 

 tudinal series of scales between the lateral line and the base of the 

 ventral. The transverse series descending forward from behind the 

 adipose fin to the lateral line is composed of fourteen scales ; all the 

 scales are obtusely rounded behind. 



Back greenish v sides and belly silveiy ; scattered black spots, 

 rather irregular in shape, and about twice as large as a scale, occupy 

 the sides above and below the lateral line. Operculum and basal 

 portion of the dorsal fin with small, round, black spots. The other 

 fins immaculate, with a blackish tinge. 



