1886 J PROCEEDINGS OF UNITED S FATES NATIONAL MUSEUM. 219 



expected of species common to Japan and California, of which the two 

 Pholads are the most noteworthy, as they have not yet been indicated 

 from the Aleutian Islands, though it seems hardly possible if found liv- 

 ing at the one locality that tliey can be absent from the other." 



]!!^^oting that the connection with Japan is rather that the northern 

 forms extend southward to Japan than that any characteristic Japanese 

 forms extend north, the final paragraph still remains unshaken. 



" The collection, though small, is valuable as closing a gap in our 

 knowledge of the geographical distribution of the mollusca of the Korth 

 Pacific, and the slight but still interesting confirmatory zoological evi- 

 dence which it adds to the hydrographic determinations which have 

 shown that the main current of the sea between Kamchatka and the 

 Aleutian chain is a cold set of Arctic water southward, and that no 

 perceptible warm northward tropical stream or branch of the Kuro 

 Siwo can be traced zoologically or hydrographically in this direction." 



It is probable that Mr. Grebnitzki sent those forms which he believed 

 not to have been represented in Dr. Stejneger's collection rather than 

 a complete series, and that he has actually a series nearly as full as 

 that enumerated here from all sources. 



Note. — Since the above was written I have examined the Gould col- 

 lection now in the State cabinet at Albany, N. Y. This has experienced 

 some vicissitudes, which may account for the fact that the shell now 

 standing for the type of Conulus ])upulus is not a Conulusat all, but the 

 young of a conical flattened Japanese Hyalina ("?) of a group entirely 

 foreign to the Kamchatkan region. The S. pauper of Gould is the shell 

 I have regarded as the adult II. floccula Mor., and which Dr. Wester- 

 lund perhaps correctly refers to a variety of R. ruderata Studer. I 

 may add that to the preceding list should be added the AcantMnula 

 liarpa Say, collected at Bering Island by the Vega, on the authority of 

 Dr. Westerlund, but not found by Grebnitzki or Stejneger. 



