418 



DB. QWYN JEFFEETS 05^ SOME 



Notice of some Shells dredged by Capt. St. J ohn, E.N., in Korea 

 Strait. By J. Gwtn Jeffreys, LL.D., T.K.S., F.L.S. 



[Bead June 20, 1878.] 



Om knowledge of tlie Invertebrata inhabiting the North-Pacific 

 Ocean has been considerably advanced by Capt. St. John's dredg- 

 ings in the Japanese and Korean Seas, as the publications of this 

 Society will testify. 



With respect to the Mollusca, I noticed in the ' Journal ' (Zoo- 

 logy, vol. xii. 1874) certain species thus procured by that excellent 

 naturalist in North Japan, which are identical with or varieties 

 of European species ; and Mr. Edgar Smith subsequently gave, 

 in the 'Annals and Magazine of Natural History ' (ser. 4, vols. xv. 

 and xvi. 1875), a list of Gastropoda from the same source. Capt. 

 St. John's last dredgings in the Strait of Korea have yielded a not 

 less abundant and valuable harvest of Mollusca ; and although I 

 prefer having the species worked out by Mr. Edgar Smith, which 

 he will doubtless do with his usual accuracy, I cannot refrain from 

 adding some remarks on a few of these species, which I consider 

 European or interesting in other points of view. 



In my former paper on the same subject I ventured to express 

 an opinion that certain species of Mollusca which are common to 

 the North-Atlantic and North-Pacific oceans might have origi- 

 nated in high northern latitudes, and have found their way to 

 Japan on the one side, and Europe on the other, by means of a 

 bifurcation of the great Arctic current. This opinion has been 

 now corroborated by Capt. St. John, who says, in his letter to me 

 of the 8th June, 1878, "It seems to me that the Arctic current 

 bifurcates, bringing similar species of Mollusca, and gradually de- 

 positing them along its course in the Pacific and Atlantic." 



I have to return my thanks not only to Capt. St. John for so 

 kindly placing these further dredgings at my disposal, but to Mr. 

 J. T. Marshall, for having laboriously and carefully sifted the 

 smaller material and picked out and assorted all the organisms 

 from it. 



BEACmOPODA. 

 Teeebeatula caput-seepentis, Linne, var. septentetonalis. 

 Anoraia caput-serpentis, L. Syst. Nat. ed. xii. p. 1153. 

 Terebratula caput-serpentis, Jeffreys, British Conchology, ii. p. 14, pi. i. 



f. 1 ; v. p. 164, pi. xix. f. 2. 

 Mab. Korea, 35 fathoms. Spitzbergen and Davis Strait to 



