CEPHALOPODA OF THE HAWAIIAN ISLANDS. 265 



origin to 0. pacificus (and sloanii ?) , and Sepioieuthis arctipinnis is similar or identical with 

 5. Icssoniana, but without exception all the species most truly characteristic of the one 

 area are conspicuous only by their absence in the other. We are able to correlate at least 

 a portion of the Japanese fauna with that of western North America much more suc- 

 cessfully. 



In summing up, then, it may be said that, although the ensemble of Hawaiian cepha- 

 lopods shows many features peculiar to itself, it appears reasonable to regard it as an 

 offshoot, now largely isolated, of the great Indo-Malayan fauna, and therefore impossi- 

 ble of any definite or satisfactory correlation with that of other regions of the north 

 Pacific. That this statement is in substantial accord with the conclusions reached by 

 students of other groups of animals is readily seen by a glance at almost any of the 

 monographs dealing particularly with the fauna of the archipelago. 



Nutting (Bulletin U. S. Fish Commission, vol. xxiii, for 1903, p. 934, 1906) in 

 discussing the hydroids says that they " have unmistakable relationship with the Aus- 

 tralian region, " although (p. 935) " as would be expected from the isolated position of the 

 Hawaiian Islands, the preponderance of peculiar species is very exceptionally large." 



Miss Rathbun reaches similar conclusions from a study of the decapod crustaceans. 

 She says that " the Hawaiian fauna is almost entirely Indo-Pacific, the islands forming 

 the northeastern, as the Indian Ocean is the southwestern, limit for the majority of the 

 species" (t. cit., p. 830, 1905). She finds but few species peculiar to the islands, however. 



Fisher (t. cit., p. 999, 1906) finds the distribution of the starfishes indicative of 

 entirely similar phenomena. He writes that "we are at once struck by the fact that the 

 Hawaiian fauna bears more resemblance to that of the distant Indian region than it 

 does to the fauna of America, notwithstanding that all the ocean currents which pass 

 the Hawaiian Islands are coming from America and not from the west." 



In the case of the shore fishes Jordan and Evermann (t. cit., p. 32, 1905) have found 

 the fauna to be "frankly and entirely tropical, all the species belonging to genera char- 

 acteristic of the tropical Pacific," but most of the species themselves seem to be peculiar 

 to the islands. 



The conclusions of Gilbert (t. cit., p. 578, 1905), after his critical examination of 

 the deep-sea fishes collected by the Albatross, are especially full of interest : "An analysis 

 of the list of species recorded in the present paper shows conclusively that the bathybial 

 fishes of Hawaii, like those of its reefs and shores, have been derived as a whole from the 

 west and south, and not from the east or north. In its entire facies, the fauna is strik- 

 ingly unlike that of the Pacific coast of Mexico and Central America, and resembles 

 strongly the assemblage of forms discovered by the Albatross and the Challenger off the 

 coasts of Japan and the East Indies. Some of its members find their nearest known 

 afimes in the Bay of Bengal." 



On the other hand, Mayer (t. cit., p. 1 133, 1906) in his report on the Medusas writes 

 that "it appears the majority of the Hawaiian forms are of wide distribution," a con- 

 clusion entirely harmonious with what we know regarding such cephalopods as are of 

 similar habit. 



