PLATE CLXX. 



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 Wey- 

 mouth. 



Having Da Costa's specimens of this shell, and also that of his 

 PectunculusVetula before us, we should not refrain from observing, 

 that the opinion of Dr. Pultney respecting hese shells is incorrect; 

 they are Hot merely transitions in growth, or varieties of the same kind r 

 the difference between the two is obvious, and fully authorize us to 

 consider them as distinct species. It should be understood in ad- 

 vancing this remark, that the shell which Da Costa figures and de- 

 scribes, for Pectunculus Vetula is clearly the Linnaean 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 con- 

 founded 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 Dorset- 

 shire,) 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 

 tlie two species are to be discriminated, in our opinion, maybe ob- 

 served in the structure of the concentric ridges on the outside of the 

 shell : these in the true Linnaean Paphia are remarkably thick, and 



