224 THE VOYAGE OF H.M.S. CHALLElStGER. 



is rendered less strange by the considerations, that it is most marked in the case of 

 the species from deep and cold water, and that the faunas of both sides of the Atlantic 

 are similarly related to the forms from the Arctic Ocean (compare regions I., II., and 

 XVII. ). 



An apparent resemblance, less easy to account for, if it be found really to exist, is 

 that between the "Western Pacific and the Western Atlantic, to which allusion has 

 already been made in the pages of this Eeport (pp. 105, 107, 184). A number of 

 identical or allied species are common to both, as may be seen from the subjoined list : — 



Western Atlantic. Western Pacific. 



Cirroteuthis lolena. Cirroteuthis magna. 



„ megaptera. „ meangensis. 



„ pacifica. 



Octopus januarii, ..... Octop)us januarii. 



Eledone verrucosa, ..... Eledone verrucosa. 



Eledonella pygmsea, .... Eledonella diaphana. 



Calliteuthis reversa, .... Calliteuthis reversa. 



It is possible that this resemblance may, upon further examination, prove to be 

 delusive. Cirroteuthis is a genus whose members appear to be rather widely distri- 

 buted in deep water; and Eledone verrucosa and Octopus januarii seem to be 

 inhabitants of moderately deep water, and wiU perhaps be dredged up from intermediate 

 points, while Eledonella is proba,bly a pelagic genus, and if so is of no weight whatever 

 in the consideration of distributional problems. It seemed worth while, however, 

 to state the facts clearly as at present known, if only for the sake of directing attention 

 to them. 



A relation between the marine faunas of Japan and Western EurojDe has been 

 pointed out in the case of fish by Dr. Giinther, and in the case of moUusca by the late 

 Dr. Gwyn Jeffreys,^ but the study of the Cej>halopoda has not made any additions to 

 the list of common forms. A matter of interest in this connection, however, is the 

 capture of specimens of Enoploteuthis in the Malay Archipelago and in the Pacific, 

 which I see no reason for distinguishing from the Enoploteuthis margaritifera of the 

 Mediterranean ; a fact which suggests the possibility of a connection having taken 

 place between the Mediterranean and the Indian Ocean, although, so far as it has yet 

 been studied, the Cephalopod fauna of the Red Sea does not lend much support to this 

 hypothesis. I understand, however, from Professor Geikie, that there is strong 

 geological evidence in its favour, and, if so, the migration which has led to the existence 

 of similar forms in the seas of Japan and Western Europe, may have taken place round 

 the south, and not round the north of Asia as has generally been supposed. 



' Jmirn. Linn. Soc. Land,., vol. xii. pp. 100-109 ; see also Hoyle, torn. cit. supra, p. V17. 



