508 Mr. R. MacAndrew on the Mollusca of Vigo Bay. 



whicli is situated six or seven miles above Vigo, and about four- 

 teen miles from the entrance of the bay. It occupies two small 

 islands connected together by a stone bridge. We had the run 

 of the larger island, which may be 200 yards in length ; it is 

 composed of granite, the component substances of which are so 

 arranged as in some parts to afford masses of talc of the bulk of 

 several inches. After diligent search I could only find five spe- 

 cies of land shells, viz. Helix aspersa, H. caper at a ^ H. cellar ia, 

 H. nemoralis, and a Helix resembling in general appearance H. 

 barbatay but toothed, the lip red. 1 obtained permission to dredge, 

 but upon condition of taking the guard in the boat with me, and 

 not passing the limits of that part of the quarantine ground ap- 

 propriated to vessels bringing clean bills of health. The locality 

 was by no means favourable, the depth nowhere exceeding three 

 to four fathoms, and the bottom consisting of filthy black mud. 

 I obtained about eighty species of shells from it, all of which, 

 with the exception of about six, are known inhabitants of the 

 British Islands ; and it strikes me as a remarkable circumstance, 

 that the mollusca of that locality are more nearly allied to the 

 British and less to the Mediterranean than those of the coast of 

 Asturias, which is further north and with a northern aspect. In 

 the latter district. Purpura lapillus which abounds here is replaced 

 by P. Hoemastoma. The neighbouring town of Redondela is 

 celebrated for its oysters, which are indeed of excellent quality ; 

 they are procured by means of a kind of rake from shallow water 

 towards the head of the lock or * via,^ and in great abundance. On 

 the 24th we were released from quarantine, anchored in front of 

 the town, and employed the following week in dredging over a more 

 extended area of the bay. The bottom, except near shore, con- 

 sists of mud, a kind of blue clay ; it varies in depth from eight 

 or ten to twenty-five fathoms. Laminarice grow in shallow water 

 as in Britain, but in no great abundance. The geological forma- 

 tion of surrounding country is all granite as far as I had an op- 

 portunity of noticing it. I annex a list of the species procured, 

 but you are not to regard it as approaching to a perfect cata- 

 logue of the shells of Vigo bay. Indeed should I, as is my pre- 

 sent intention, spend a week there on my way back to England, 

 I hope to make considerable additions to the list. It is not 

 necessary to call your attention to the singular fact that all the 

 strictly littoral shells are identical with British species. The 

 only exception that occurs to me is the Mytilus Gallo-provincialiSj 

 and that is doubtful. Chiton rufus, Fusus contrarius and some 

 others, though occasionally found alive upon the shore, I do not 

 consider to be littoral species. I was much interested in finding 

 the last-named shell {Fusus contrarius) living. You will notice 

 that I have again met with our acquaintance Chemnitzia fene- 



