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ON A NEW SPECIES OF AMPULLARIA.

BY THE REV. J. E. TENISON-WOODS, F.G.S., F.L.S.,Corr. Mem. Roy Soc. Tas., Sydney, &c.

[Read 11th July, 1876.]

 

I beg to bring under the notice of the Society a new species of Ampullaria, a genus hitherto unknown in the Australias. Some time since I described all the known freshwater shells of the island which duly appeared in last year's transactions. Since then I have described a new Valvata, V. tasmanica which was discovered by that most industrious entomologist, Aug. Simson, who obtained it from a creek in Gould's Country. Since then in looking over some shells kindly placed at my disposal by Ronald Gunn, Esq., F.L.S., I have found the Ampullaria which I now describe. It is small in size, but very interesting from the fact that it is the only species of that very large genus which has yet been found in any part of Australia. For­tunately, though the collection of individuals was small, yet the most of them had the operculum in situ, which enabled me to pronounce that it is Shelly. The genus has only been studied of late years, and is found best repre­sented in South America, where it attains a large size, and presents beautiful varieties of colouring. I was unable to ascertain the precise habitat from Mr. Gunn, who was, however, certain that it was obtained from some of the rivers emptying themselves on the north coast.

AMPULLARIA. TASMANICA n.s. A.t. parva, subglobosa, cornea, spira brevi, obtusa, epidermide atro-olivacea, induta; anfractibus 4, subito decrescentibus; apertura lata, simplici, postice angutata; labio alba, conspicua, concava, reflexa, fauce oetate albicante. Operculum subconvexum, loevigatum epidermide (?) olivacea indutum.

Shell small, subglobose, horny, with a short obtuse spire; epidermis blackish olive; whorls 4, rapidly decreasing, aperture wide, simple, angulate posteriorly, inner lip white conspicuous, reflexed, concave; throat becoming whitish with age. Operculum, sub convex, smooth, with an olive epidermis (?) Diam. maj. 3 1/2, min. 3 mil.

This little ampullaria has no determinate characters except its small size, dark color, and white concave inner lip. The penultimate whorl is rather gibbous.