2. OlfCORHTNCHUS. 



155 



ninth of the total length. Jaws of equal length, armed with small 

 teeth. Tongue with ten or twelve teeth on each side ; also the end 

 of the hyoid bone isi armed with smaU teeth. Body with ten or 

 twelve cross bands, without other markings. 



Eight and a half inches long. Eiver de la Mana. 



2. ONCOEHYNCHUS. 



Oncorhynchus, SuckUy, Ann. Lye. Nat. Hist. 1861, p. 312. 

 Body covered with smaU scales. Cleft of the mouth wide, the 

 maxiUary being long, lanceolate, extending behind the orbit in the 

 adult fish; adult males with both jaws hooked and armed with very 

 large teeth. Teeth on the shaft of the vomer, but generally lost 

 with age ; teeth on the tongue present ; none on the hyoid bone. 

 Dorsal fin short ; anal fin rather long, with more than fourteen rays. 

 Pyloric appendages in great number. Ova large. 



Migratory fish, ascending the American and Asiatic rivers flowing 

 into the Pacific. 



Although we adopt the genus proposed by Dr. G. Suckley, we 

 found it upon a character entirely neglected by that author, namely 

 the elongate anal fin, caused by an increased number of the rays, 

 which is of greater importance than the hook-like production of the 

 upper and lower jaws in the males. 



1. Oncorhynchus lycaodon. 



Specimen a ; two-thirds the natural size 



Salmo lycaodon, Patt. Zoogr. Ross.-As. iii. p. 370. 



japonensis, Pall. I. c. p. 382 (female). 



dermatinus, Richards. Voy. Herald, Zool. p. 168, pi. 33. figs. 3-5 



(old male, after spawning ; the praeoperculum, which is shrunk in 

 the typical specimen, is represented too narrow). 



consuetus, Richards. I. c. p. 167, pi. 33. figs. 1, 2 (male, not full- 

 grown). 



