508 Mr. R. MacAndrew on the Mollusca of Vigo Bay. 
which 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 tale of the bulk of 
several inches. After diligent search I could only find five spe- 
cies of land shells, viz. Helix aspersa, H. caperata, H. cellaria, 
H. nemoralis, and a Helix resembling in general appearance H. 
barbata, 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. Hemastoma. 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. Laminaria 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-provincialis, 
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) livmg. You will notice 
that I have again met with our acquaintance Chemnitzia fene- 
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