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Show 378 MR. E. A. SMITH ON THE [Apr. 18, has five or six lines on the penultimate whorl, and is a more elevated shell than C. consanguineum ( = obsoletum, Rve.), in both these respects agreeing very well with C. madagascariense of Gray, which I consider almost identical with, or at most only a slight variety of, C. unicarinatum of Lamarck (non C. unicarinatum of Sowerby, Pfeiffer, and Reeve, = G. fulvifrons, Sowerby). CYCLOSTOMA JOHNSONI, sp. nov. (Plate XXI. figs. 4, 5.) Shell small but thickish ; white, with a single purple-brown zone a little below the middle of the body-whorl; openly umbilicated, finely lirate upon the spire, smoother upon the last volution, especially on the lower surface, striated by lines of growth. Whorls 5, convex, separated by a deep suture, first two smooth, the third with about five fine spiral lirse, the penultimate with about eight rather finer ones, increasing in number but much more feebly developed upon the upper half of the last whorl, and quite obsolete beneath the periphery, and scarcely traceable within the umbilicus. Aperture a trifle oblique, subcircular, a little longer than wide, white, with the single band. Peristome continuous, expanded all round, rather more so on the columellar side than on the opposite margin. Greatest diameter 14 millim., height 13| ; aperture 8 long, 6§ wide. Hab. South of Trabonjy, north-west central part of Madagascar (Johnson). This very interesting species is not likely to be confounded with any previously described ; and I have much pleasure in associating with it the name of its discoverer. It is a comparatively smooth shell, characterized by the simplicity of its coloration and the non-lirate lower surface of the body-whorl. CYCLOSTOMA LINEATUM, Pfeiffer. Cyclostoma lineatum, Pfeiffer, Conch. Cab. pl. 45. f. 3, 4 ; Smith P. Z. S. 1881, p. 278 (as var. of O. insulare, Pfr.). Hab. Valley of Marohogo near Mojonga, north-west Madagascar (Johnson). The specimen from the above locality is exactly similar in all respects to the type of this species, which at one time I considered a variety of C. insulare. As the localities prove to be different, I now think it better to keep the two forms separate. Some small varieties of C. insulare from the country between Lake Nyassa and the east coast of Africa, referred to by me in the ' Proceedings,' approach very closely the present species. None of them, however, are absolutely identical, the umbilicus being a little more contracted, the spire a trifle lower, and the liration around and within the umbilicus decidedly coarser. In C. lineatum this is unusually fine. Pfeiffer described the shell as smooth; but this is not correct. To the unaided eye such appears to be the case; but on making use of a lens, the fine brown lines are seen to be elevated (lira), and the lines of growth are by no means inconspicuous. The spiral lines number about twelve on the penultimate whorl, alternately fine and |
