VELUTINA. 335 



consist almost entirely of epidermis, with a small deposition of cal- 

 careous matter within. The ordinary English specimens are said 

 to be of about the size of a pea, or perhaps twice as large ; but it 

 sometimes becomes three fourths of an inch in diameter. I sent 

 our ordinary specimens to Mr. G. B. Sowerby, who sent larger 

 ones in return, assuring me of their identity. These differ from 

 the shell as we find it, in being more solid, the epidermis more 

 wrinkled lengthwise, the surface shining where this is removed, 

 and the lowest whorl is disunited from the preceding one at the ap- 

 erture. These changes may all be attributed to age. We may an- 

 ticipate finding specimens of equal size here, since we have already 

 found them four times as large as the one described by Mr. Conrad, 

 who allows the very close affinity of his minute one to the Icevigata 

 of Europe. 



The quoting of Bulla veliitina by Lamarck, as a synonyme to his 

 Sigaretiis haliotoideus, is plainly erroneous. The Helix haliotoidea 

 of Fabricius, which is the Bulla velutina of Miiller, is not the H. 

 haliotoidea of Linnteus and others ; and hence the probable mis- 

 quotation. 



The figure in Pennant's "British Zoology " is poor; that of Blain- 

 ville represents the common appearance when arrived at that size, 

 the transverse wrinkles becoming more conspicuous than the revolv- 

 ing ones, which evidently become obsolete with age. The white 

 zone, which he represents, however, I have never seen. Brown's 

 figure is very good for a shell of the size, and Conrad's is sufficiently 

 characteristic for specimens as we usually find them. 



St. Anne {Bell} ; Halifax, Banks ( Willis) ; Eastport, twenty 

 fathoms ( Cooper) ; Marblehead (^Haskell) ; Cape Cod, northwards 

 (^Slimpson). 



Velutina zonata. 



Fio. 160. 



Shell oval-orbicular, compressed, pellucid, covered with a striped, calcareous 

 incrustation ; inner lip flattened and channelled. 



Velutina zonata, Gould, Inv. 1st ed. 242, fip. 160. -De Kay, N. Y. Moll. 1,54, pi. 23, fig. 

 253. — Reeve, Conch. Syst. i. pi. 147, figs. 3, 4. — Stimpson, Check Lists, 5. 



Shell thin, opaque, white, and in some places pellucid, minutely 

 striated both ways ; whorls less than three, the first two minute, 

 and not seen when the shell is viewed in front ; the last, widening 

 with great rapidity, becomes large, though it is not tumid, but ap- 



