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Show 456 MR. HARPER PEASE ON POLYNESIAN LAND-SHELLS. [May 2, latter proved to be a synonym of Theba, Leach. He cites four species as types: the first, II. corne, I do not find mentioned by any other author, and has not been published ; the three remaining are from Polynesia and agree in their characters, leaving no doubt as to the genus intended; they are brunnea, Anton, =glandula, Beck, subtilis, Anton, = vitrinella, Beck, and orbis, Beck. The animal of the species I have had an opportunity of examining is rather slender and elongate, tapering gradually posteriorly to a point, and provided with a glandular opening, slightly raised, at about an equal distance between the extremity of the foot and the shell; the mantle wholly included within the shell. They should therefore be arranged in the family Stenopidce, under the genus Ariophanta, rather than Nanina. The species enumerated in the following catalogue vary considerably from the type; their generic relations cannot be determined until the animals have been examined. The columella of the typical species is simple, occasionally slightly everted; in others it is more or less callous, sometimes dentately so, or the callosity is transverse to the columella. The type is a depressed form, orbicular in shape, either rounded at the periphery or slightly angulate; other species are acutely angulate, assuming a trochiform shape, one form of which M . Mousson has lately separated under the generic name of Trochonanina. Other species assume a conical shape, such as H. cultrata, Gld., and conula, Pse., which would, by some authors, be rauked under the European genus Conulus. Genus TROCHOMORPHA, Alb. TROCHOMORPHA TROCHIFORMIS, Pfr. The above is one of several Ferussacian species which appear by name in his * Prodrome,' of which the types are probably lost, as they are not described in his great work on land-shells, nor recorded by M . Deshayes. The first description of the above is that by Dr. Pfeiffer, from a Tahitian species, which is generally accepted as the type, although the locality given by Fe'russac is the island of Mauritius. As there is at least a doubt as to the species originally named by Fe'russac, I think proper to attach the name of Dr. Pfeiffer to the above as author. I have received several distinct species from collectors under the name trochiformis, Fer. Dr. Pfeiffer's type inhabits the island of Raiatea. It occurs of larger size, and occasionally wholly dark brown or wholly pale yellow ; a variety is rarely met with more depressed than the type, of a whitish or pale yellow colour encircled by a single narrow dark brown line or band ; base ornamented the same. On the island of Moovea, where the species also occurs, this variety prevails and assumes the size and shape of the type. On Tahaa, adjoining Raiatea, the type occurs of smaller size and •-•ore conical in shape. |