1. SALMO. 53 



iuclies. 



Greatest depth of operculum 1 



Distance between occiput and origin of dorsal fin . . 3f 



Distance between end of dorsal and root of caudal . . 4-j^ 



Length of base of dorsal If- 



Greatest height of dorsal l^g 



Length of pectoral 1|^ 



Distance between root of pectoral and root of ventral 8^ 



Length of ventral fin 1^ 



Distance between root of ventral and origin of anal . . 2f 



Length of anal fin 1 



Greatest depth of anal If 



Length of longest caudal ray 1-L| 



Length of middle caudal ray ^ 



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

 fin, and is very little less than one-fourth of the entire length (with- 

 out caudal) ; the length of the head bears about the same proportion. 

 The snout is moderately produced, conical, and is a little more than 

 half the length of the postorbital portion of the head ; the lower jaw 

 has no hook, and the mouth closes perfectly ; the length of the max- 

 illary bone exceeds that of the snout by nearly two-thirds of the dia- 

 meter of the eye, its greatest width- being equal to about one-half 

 of the same. 



The maxillary and palatine teeth are considerably smaller than 

 those of the intermaxillary and mandible. The head of the vomer is 

 triangular and broader than long. Of the vomerine teeth there re- 

 main three situated on the ridge of the hinder margin of the head of 

 that bone, and three pairs on the longitudinal ridge, one of each pair 

 being bent to the right, the other to the left ; there is also a single 

 conical tooth at some distance behind the last of these pairs. 



The praeoperculum has the whole hinder margin rounded, the lower 

 limb not very distinct, and a shallow notch above the angle. The 

 hinder margin of the operculum is almost straight, oblique, and forms 

 a right angle with its lower limb. A line from the upper end of the 

 gill-opening to the opercular angle exceeds in length another line 

 from the latter point to the lower anterior end of the suboperculum 

 by one-fourth of the latter Une. 



The (Ustance of the origin of the dorsal fin from the occiput, if 

 carried back from behind that fin, reaches halfway between the atli- 

 pose and the root of the caudal. 



The dorsal fin is a little longer than high, and consists of fourteen 

 rays, of which the first three are rudimentarj' and enveloped in the 

 skin, the fourth simple, considerably, shorter than the fifth, which is 

 also simple and nearly equals the sixth in height, the latter being 

 the first branched ray and the longest of the fia ; the last ray is cleft 

 to the base. 



The length of the base of the anal fin is one-third of the height 

 of that fin, which consists of eleven rays, the two anterior ones being- 

 rudimentary and enveloped in skin, the third simple and e(]ual to 

 the fourth, which is branched ; the last ray is cleft to the base. 



