18 SALMONID^, 



inches. 



Greatest width of tlie operculum 2^ 



Greatest depth of the opercvilum ^ . . . 2f 



Distance between the occiput and the origin of the 



dorsal fin 10| 



Distance between the end of the dorsal and the root 



of the caudal fin 11 



Length of the base of the dorsal 3f 



Greatest height of the dorsal 3|^ 



Length of the pectoral 4^ 



Distance between the root of the pectoral and the 



root of the ventral 9| 



Length of the ventral fin 3|- 



Distance between the root of the ventral and the 



origin of the anal . 6^ 



Length of the anal fin 2 



Greatest depth of the anal 3 



Length of the longest caudal ray 4|- 



The specimen is out of condition, and had evidently finished 

 the work of propagating its species. The skin over the whole of 

 the body, and especially on the back and along the root of the 

 fins, is much thickened and fungous, so that only the apex of the 

 scales remains visible. The greatest depth of the body is below the 

 origin of the dorsal fin, and one-fourth of the total length (the 

 caudal fin not included). The head is long, rather more than two- 

 sevenths of the total length, the snout being so much elongated that 

 the eye occupies exactly the middle of the distance between the end 

 of the snout and the operculum ; the hook of the lower jaw is so 

 much developed that the bony and cartilaginous part together form a 

 complete semicircle ; the cartilaginous part is one inch long : a deep 

 hollow in the upper jaw receives the hook ; however, the mouth 

 cannot be completely shut, and the finger can easily pass between 

 the jaws when closed. The maxillary bone is shorter than the 

 snout, and extends scarcely beyond the vertical from the posterior 

 margin of the orbit, the width of its broadest part is less than the 

 diameter of the eye. 



The dentition of the jaws and of the palatine bones is almost per- 

 fect ; the teeth of the intermaxillary being stronger than those of 

 the mandible, which again are larger than the maxillary and pala- 

 tine teeth : the series of intermaxillaiy teeth does not extend across 

 the fore part of the snout, the intermaxillary bones themselves being 

 separated by a deep notch. Of the vomerine teeth three only of the 

 anterior ones are left, they form a triangle : most of the teeth of the 

 tongue are lost. 



The distance of the nostrils from the orbit equals the diameter of 

 the latter ; the interorbital space is very convex, the orbit being far 

 below the upper profile of the head ; its width is less than the length 

 of the maxillary bone, and equal to the distance between the eye 

 and the angle of the praeoperculum. The posterior margin of the 



