JORDAN AND JORDAN: FISHES OF HAWAII. ' 31 



Family LXII. SCOMBRID^ (Mackerels). 

 Pneumatophorus Jordan and Gilbert. 

 212. Pneumatophorus japonicus (Houttuyn). Opelu palaJm. (J. & E., p. 169.) 

 This small mackerel is rather rare about Hawaii. It needs comparison with 

 the abundant geminate forms, P. japonicus of Japan and P. diego -hom California. 

 P. colias of Europe and P. grex of our Atlantic coast also differ slightly, though 

 all are very much alike. The "Chub-mackerels," Pneumatophorus, differ from the 

 mackerel of commerce, Scomber, in the development of the air-bladder. 



■^i^i' 



Fig. 2. Istiophdrns yhtdim (Brous.sonet). From a cast in the Beniice Pauahi Bishop Museum, Hoiiohilu. 



Auxis Cuvier (Frigate-mackerels). 



213. Auxis thazard (Lacepede). (J. & E., p. 171.) 



This pelagic fish requires to be compared with .4. rochei of the Atlantic and 

 A. tapeinosoma of Japan. 



EuTHYNNUS Liitken (Oceanic Bonitos). 

 (We let this genus* stand until it can be compared directly with Gymnosnrda 

 unicolor, the tyjie of the allied genus Gymnosarda.) 



214. Euthynnus pelamis (Linnaeus). Aku. (J. & E., p. 172.) 



This fish of the open sea is now very abundant in the markets of Honolulu 

 and Hilo. It is extensively canned for commerce; more than any other species. 

 The flesh is red, rather coarse, and oily. The better species of this group are not 

 put up in tins, their use as fresh fish being more profitable. The best of them sell 

 at present at fifty cents a pound in Honolulu. The various forms of striped "Oce- 

 anic Bonitos" found in the warm parts of the Atlantic and Pacific need comparison 

 one with another. 



215. Euthynnus alleteratus (Rafinesque). Kciwakdiva. (J. & E., p. 173.) 



Very common in the markets. The young are taken in nets in the shallow 

 waters of Hilo Bay. The flesh is paler than that of the Aku, and brings a higher 



