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Show 120 MR. G. NEVILL ON THE [Feb. 17, HELIX (XEROPHILA) CESPITUM, Drap. This species, also near Menton, appears to differ widely, and, at the same time, constantly, according to the altitude at which it lives ; it is interesting to notice, in the " Couche marneuse " at Cape Mortela, how an allied species, with narrow umbilicus, either Helix ferneri or a closely connected form, abounded at a certain depth, associated with H. paretiana, how this species suddenly ceases at a certain distance from the surface, its place being taken by the widely umbilicate II. cespitum. Var. DISMASTHIA, nov. Spire very little raised, often nearly quite flat, rather solid ; whorls seven, scarcely convex; last whorl compressed, scarcely descending, not tumid at base ; umbilicus less open than in most forms of H. cespitum ; aperture rather compressed, slightly produced, columellar margin very oblique; vividly coloured; above coarsely but regularly and closely striate, striae subobsolete at base. This form is abundant near the sea only, apparently not found at any considerable altitude, where its place is markedly taken by the next variety; I found it also at Alassio, near Genoa. A curiously coloured form, common at both places, was of a nearly uniform dark brown above, with a bright yellow belt at the periphery. Alt. 12£, diam. 21} millim.; apert. alt. 9}, lat. 10f millim. Var. ALTICOLA, nov. Like the preceding a well-marked, characteristic, and constant variety ; the two forms apparently do not, at Menton at least, run into one another; the two almost seem to me specifically separable; some conchologists will doubtless consider them so; the anatomist will have to settle the question. At an altitude of 2000 feet for certain (perhaps sooner), var. alticola takes the place of var. dismasthia and is found in great abundance up to the very summits of the mountains, over 4000 feet. Spire moderately raised, almost smooth; the upper whorls sub-obsoletely striate, openly and solariformly umbilicate, texture a good deal thinner than in the preceding var.; whorls seven, convex, last whorl globosely rounded, tumid at base; aperture nearly perfectly round, the interior as high as broad, outer margin descending more abruptly, the columellar one markedly less oblique, the peristome less thickened within; coloration, above especially, less vivid. Alt. 18, diam. 27-J; apert. alt. 134;, lat. (curn marg.) 14 millim. For comparison with the two preceding measurements, I give below those of IL cespitum and its var. major as recorded by Pfeiffer (Mon. i. p. 161). Diam. maj. 20, alt. 11 millim. Var. major-diam. maj. 25, alt. 14 millim. Types of the two preceding varieties in Indian Museum, Calcutta. HELIX (XEROPHILA) SUBCESPITUM, n. sp. I found a few subfossil specimens of this undoubtedly distinct |