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Wales, by which he could only mean that the species is an inhabitant of the Menai, the arm of Beaumaris bay, communicating with the St. George's channel which divides Caernarvonshire from the island of Anglesea. The same writer notes it likewise from Cornwall. Dr. Pultney describes it as a scarce shell, which he had found at Weymouth.

Having Da Costa's specimens of this shell, and also that of his Pectunculus Vetula before us, we should not refrain from observing, that the opinion of Dr. Pultney respecting these shells is incorrect; they are not merely transitions in growth, or varieties of the same kind, the difference between the two is obvious, and fully authorize us to consider them as distinct species. It should be understood in advancing this remark, that the shell which Da Costa figures and describes, for Pectunculus Vetula is clearly the Linnæan Venus Paphia, a shell well known as a native of the West Indies, and never found to our knowledge in any of the European seas. Da Costa was aware, after his work had been published, that he had erroneously confounded the variety of Fasciatus, Fig. 1, 1, in our Plate, with the West Indian shell; he had conceived the latter to be the same shell in a more perfect condition, and caused it to be engraved accordingly.

- Dr. Pultney, in the passage wherein these shells of Da Costa are noticed (in his catalogue of the shells found on the coast of Dorsetshire,) describes the Pectunculus Fasciatus as nothing more than a variety of Venus Paphia (Linn.) in which respect he is assuredly mistaken. One of the most striking characters, by means of which the two species are to be discriminated, in our opinion, may be observed in the structure of the concentric ridges on the outside of the shell: these in the true Linnæan Paphia are remarkably thick, and

prominent in the middle, but in approaching each extremity become suddenly obtuse, and are then continued in an attenuated ridge, particularly as they extend towards the front of the shell, and thus exactly corresponding with the definition of Linnæus, "rugis incrassatis, pube rugis attenuatis." On the contrary, in our shell the ridges are nearly of an uniform thickness throughout, sloping gradually with the depression of the shell behind, and only terminating abruptly at the edge of the front, or fore part of the shell where the valves appear obtuse: the outline of the shell is also very different from Venus Paphia, the latter being more produced on each side than our Venus Fasciata.