Wrinkled Apple Snail.
Generic Character.—See Pl. 103.
- A. testâ globosâ, corrugatâ, olivaceâ; spiræ prominentis, acutæ, anfractibus ventricosis; aperturæ margine crasso, fulvo, sulcato; umbilico parvo, juxta labii interioris mediam posito; operculo testaceo.
- Shell globose, wrinkled, olive; spire prominent, acute, the whorls ventricose; margin of the aperture thick, fulvous, grooved; umbilicus small, linear, near the middle of the inner lip; operculum shelly.
- Helix Ampullacea. Linn. Gmelin, p. 3626.
- Ampullaria rugosa. Sowerby, Genera of Shells, fas. 4. fig. 1. 2.
The annexed figures of this hitherto undefined species will clearly show its distinction from Amp. globosa, (pl. 119); and the specific characters now framed for these two shells, will, I think, sufficiently distinguish them from each other.
In comparison with A. globosa, this (even in the young state) is a wrinkled, not a smooth shell, having the umbilicus placed near the middle, not towards the base, of the inner lip: the spiral whorls are elevated and ventricose, not depressed, and slightly convex; and the basal volution, instead of being very wide on the upper part, (near the suture,) is widest only in the middle. In young shells, the wrinkles and the marginated aperture are less defined. When divested of its epidermis, the colour is blueish white, with a few narrow bands of obscure purple. A specimen in my own collection has the epidermis so thin, that the colours beneath it are very conspicuous. The mouth inside is dark chesnut, with blackish bands; the margin being pale yellow and slightly reflected. The umbilicus, both in this and in A. globosa, is small and contracted, while in the real A. rugosa Lam. (Helix urceus Lin.) it is very large, round, and deep. This latter shell, also, differs from both of the former, by having a thin, and not a margined aperture.
Mr. Sowerby appears the only writer who has figured this shell, which he has mistaken for the A. rugosa of Lamarck. I am informed by Mr. Humphreys it is a native of India.