]_00 DK- GWYN JEFFREYS OK 



On some species of Japanese Marine Shells and Fishes, -which 

 inhabit also the Nortli Atlantic. By J. Grwrs Jeffreys, 

 LL.D., F.E.S., F.L.S. 



[Read January 15, 1874.] 



During the survey made by Capt. St. John in H.M.S. ' Sylvia ' 

 of the coasts of Japan between 43° 34' and 33° 23' N. lat., and 

 145° 20' and 131° 40' E. long., in the years 1871 and 1872, the 

 dredge was occasionally used ; and the results have been kindly 

 placed at my disposal by Capt. St. John and tlie Hydrographer 

 Eoyal. All tlie specimens of natural history, except those shells 

 which I now propose to notice, have been placed in the British 

 Museum. 



Our present knowledge of the geographical distribution of the 

 marine MoUusca is so imperfect that any contribution to the 

 subject cannot but have its value. The accuracy of Capt. St. 

 John's hydrographic surveys is universally recognized ; and I 

 will endeavour to be equally careful in determining and naming 

 the Japanese shells, which, on comparison with those from Euro- 

 pean seas, I regard as belonging to the same species. I am quite 

 aware of the difference of opinion entertained by many experi- 

 enced conchologists as to the identity of species which inhabit 

 widely separated tracts of the ocean, and that such species are 

 called by some conchologists "representative " instead of identi- 

 cal ; but certain species (e. g. Saxicava rugosa or arcticct) unques- 

 tionably have a world-wide distribution. Moreover the love or 

 ambition of species-making is perhaps inherent in the nature of 

 many naturalists, however conscientious they may be. For my- 

 self I would renew my expression of unqualified approval of the 

 opinion entertained by the learned authors of the ' Flora Indica,' 

 that the discovery of a form uniting two others previously thought 

 to be distinct, is much more important than that of a totally new 

 species, inasmuch as the correction of an error is a greater boon 

 to science than is a step in advance. The variation of species 

 among the Mollusca cannot be less than among plants. 



The marine shells of Japan have been noticed and described by 

 several writers, from Carl Peter Thunberg in 1788 to Dr. C. E. 

 Lischke in 1872. This last excellent conchologist gave, in tlie 

 first volume of his ' Mollusca Japonica,' a valuable synoptical 

 table of those species which inhabit other parts of the world. 

 He showed that the following species are common to Japan and 



