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Show 260 MR. E. A. SMITH ON THE [Apr. 5, species which have much the same type of form ; but this supposed resemblance, in reality, proves to be less, on a careful comparison of the two types, than one at first would imagine. Perhaps the most striking similarity to Pacific forms occurs among the Patulce. Such species as P. radiella, Pfr., P. multilamellata, Garret, P. aculicostata, Mousson, and others from the Polynesian Archipelago are exact representatives of the Endodontce, or toothed group of Patulce, from St. Helena. Still, although these Pacific forms are certainly of the same type, we must also remember that the same form of Patula occurs in the island of Fernando Noronha, namely, P. quinquelirata, Smith, and possibly also on the adjacent mainland of Brazil itself, although its presence there has yet to be discovered. In the following complete list of the indigenous species references are not given, as they are obtainable by consulting Mr. Wollaston's work. In conclusion I propose to discuss one or two of the introduced species. A. Indigenous Species. 1. VlTREA MELLISSII (Wollaston). This minute species, which is known to m e only by description, is possibly an introduction. PATULA (without teeth). • 2. P A T U L A S P U R C A (Sowerby). (Plate X X I . figs. 1, 1 a.) This species was unknown to Mr. Wollaston, and consequently being misled by the somewhat poor figure given by Forbes, he has placed it in the genus Hyalina (=Vitrea). The examination, however, of a number of specimens, some received from Mr. Alexander, who furnished Forbes with his examples, others from Capt. Turton, proves that it should be located in the group Patula. Sowerby's description being so brief, I think it advisable to recharacterize it, thus :- Testa anguste umbilicata, suborbicularis, tenuis, albida, rufo-variegata, haud nitida j spira parum elevata,ad apicem obtusa; anfractus 5, convexiusculi, regulariter et lente accrescentes, lineis increment^ tenvibus confertis fexuosis obliquis striati, ultimus ad peripheriam rotundatus, antice haud descendens ; apertura late lunata, simplex, hand dentata vel Virata ; peristoma tenue, margine columellari leviter expanso et reflexo. Diam. mag. 5 millim., inin. 4\, alt. 3|; apertura 2\ longa, 1| lata. Hab. Sugarloaf Hill and Quarry (Turton). Extinct (? living). In some specimens the spire is more elevated than in others, and occasionally the apex is scarcely raised above the last whorl. The majority of the examples examined have to a great extent lost their original colour and are now of a uniform whitish tint; but a few from Sugarloaf Ridge, which have the appearance of live shells, look of a pale reddish colour to the naked eye, but when viewed under a |