JORDAN AND THOMPSON: FISHES OBTAINED IN JAPAN IN 1911. 211 



the back from the occiput to the insertion of the dorsal is a rather firm rod of tissue 



immediately below the skin. Having but the single specimen, we are unwilling to 



dissect it to ascertain the nature of this structure. 



This is probably distinct from Nansenia groenlandica described from a single 



specimen from Greenland, but Reinhardt's scanty account indicates no certain 



difference. 



Family SALMONID^. 



19. Oncorhynchus keta (Walbaum). 

 (Mem. Carn. Mus., Vol. VI, p. 9, fig. 8). 

 Sendai. 



A breeding male, weighing 8 pounds; greenish, side silvery, barred with dirty 

 crimson; no spots; top of dorsal black; A. 14, D. 12 or 13. Gill-rakers 10 + 13. 

 Scales 130. Pyloric ca?ca about 100. Flesh orange, rather soft, becoming pale 

 and mushy when cooked, palatable, but, at the best, much inferior to that of the 

 Masu. 



This species, the Dog Salmon or Cahco Salmon of Alaska, is the large salmon 

 or Sake of Japan. It is very extensively salted, the flesh when salted being quite 

 red. It ranges southward as far as the Tonegawa, north of Tokyo. No specimen 

 in the Carnegie Museum. 



20. Oncorhynchus masou (Brevoort). (Plate XXIV, fig. 3.) 

 {Salmo macrostomus Giinther). 



Lake Biwa, Sendai, Lake Chuzenji (planted in latter locality). No. 6002a. 



The Masu, the young being called Yamame or Yamabe, is a species close to the 

 Silver Salmon (0. kisutch) of Alaska. It is common as far south as Lake Biwa, and 

 is sometimes landlocked, as in Lake Chuzenji, where it has been artifically intro- 

 duced. This is a true Oncorhynchus, all its individuals dying after spawning. 

 There is no true trout, that is, no species of Salmo, native in Japan. 



The salmon called Oncorhynchus yessoensis is not known to the Japanese 

 Bureau of Fisheries and is probably not different from 0. masou. 0. kisutch is not 

 certainly known from Japan, the specimens thus far called by that name being 

 0. masou. Mr. Tokishiro Koshida of the Bureau of Fisheries informs us that the 

 king Salmon, Oncorhynchus tschawytscha, known as " Masunosuke," or Lord of the 

 Salmon, is found in Nemuro and occasionally as far south as Hakodate. 



The " Benimasu " or Red Salmon, Oncorhynchus nerka, is common in Nemuro 

 and landlocked in the lakes of that region. Oncorhynchus masou is known in 

 Lake Chuzenji as " Hinemasu." It was introduced there from Akita, and has 

 become landlocked. 



