205 



ON SOME MOLLUSCA FROM BERING SEA, WITH DESCRIPTIONS 

 OF TWO NEW SPECIES OF TROCHID^. 



By Edgae a. Smith, F.Z.S., etc. 



Head llth November, 1898. 



The specimens here described were collected at the Commander 

 Islands in 1896 by Mr. G. E. H. Barrett - Hamilton, who, with 

 Professor D'Arcy Thompson, had been instructed by the Government 

 to investigate the natural history of the JSTorthern Eur-Seal, at the 

 fur-seal islands of the North Pacific. Some account of the 

 Mollusca of these islands, which are situated in the Bering Sea, has 

 been given by Dr. W. H. Dall.^ Although Mr. Barrett-Hamilton 

 collected but five species of Mollusca, it is curious to find that only 

 one of these appears in Dr. Dall's list, viz., Valvatella Beringensis, 

 which he catalogues as a form of Margarita helicina, but this, for 

 reasons hereafter given, is, I think, sufficiently distinct to be entitled 

 to specific rank. In using the generic name Valvatella in preference 

 to Margarita, I follow the course adopted by Mr. Melvill in his 

 presidential address to the Conchological Society in 1896.^ Dall and 

 Pilsbry, on the other hand, prefer the use of Margarita, because, 

 although a synonym, it had been commonly in use for many years.^ 

 The whole question of the employment of such names rests upon the 

 application of the rules of nomenclature being made retrospective 

 or not. For my own part I think the former the best course to adopt ; 

 for, although it may cause temporary inconvenience, such alterations 

 soon become established, especially when incorporated in some 

 recognized manual. Many of the Lamarckian names, for instance, 

 universally employed during the first half of the present century — 

 e.g., Ricinula, Ancillaria, Cassiclaria, Navicella, Rotella, Tornatella, 

 Aspergillum, etc., etc. — have now disappeared from recognized 

 nomenclature, and it will be the same with others, such as Margarita, 

 the one in question, if the alterations pointed out are noted and 

 followed. The species in the present collection are : — 



1. Ommatosteephes, sp. 

 A small species about two inches in length. 



1 Proc. U.S. National Museum, toI. vii (1884), pp. 340-349; vol. ix (1886), 



pp. 209-219. 

 - Journ. Conch., vol. vii, p. 472. 

 ^ Bearing this in mind, it is somewhat surprising to find that Mr. Pilsbry has 



made use of the name Tethys for the sea-hares, instead of the generally accepted 

 ■ term Jpli/sia (Man. Conch., ser. i, vol. xvi, p. 65). 



