OCR Text |
Show 112 COL. R. H. BEDDOME ON NEW [Mar. 5, 3. Descriptions of Land-Shells from the Island of Koror, Pelew Group. By Col. R. H. BEDDOME. [Received February 19, 1889.] (Plates XI. & XII.) The following interesting shells were collected for Dr. Hungerford by Mr. Gibbon, who resides in Koror, or Coror, one of the Pelew Islands. 1. DIPLOMMATINA LUTEA, sp. nov. (Plate XI. figs. 1, la.) Shell sinistral, broad ovate, not rimate, thick, yellowish, irregularly blotched with black towards the apex: whorls §\-7, gradually increasing downwards, the penultimate being the largest; sculpture a fine, close, regular oblique striation across all the whorls, last whorl ascending much on to the penultimate; a slight constriction on the penultimate, just above the columellar margin : peristome very thick, 3 breadth of shell, dilated at its outer margin; inner lip much expanded, shining, continuous round the apex of the aperture, where it is faintly striated across: aperture vertical, subquadrate, furnished with a tooth-like process on the columellar margin, which is lamellalike, running back into the shell. Length 3| millim. Hab. Koror. The peristome of this and the five following species is of very great thickness in comparison with the size of the shell, much more so than in any Indian species with which I a m acquainted; it might be misguiding to describe the peristome as double in these species when the outer margin is dilated, and single when there is no dilatation, as this dilatation certainly varies in different individuals of the same species and may be altogether absent, or more or less prominent in the same species. I do not see how the subgenus Palaina can be kept up for these Pacific species of Diplommatina, as they differ more amongst themselves than many of them do from Himalayan forms, and the same may be said of Diancta and Paxillus. 2. DIPLOMMATINA PLATYCHEILUS, sp. nov. (Plate XI. figs. 2 a.) Shell sinistral, ovate, fusiform, thick, inconspicuously rimate, dull brick-coloured : whorls 6|-7 : sculpture, the upper lg-2 minute whorls glabrous or very finely striated, the 3rd and 4th with prominent coarse, rather thick ribs, the antepenultimate partly furnished with similar ribbing, and partly with a close fine striation, penultimate finely striated, the last whorl furnished with a few swollen convex ribs ; penultimate much the largest, and most swollen, with a slight constriction above the columellar margin ; last whorl not ascending much on to the penultimate: peristome very thick, about 3 breadth of shell, finely costulate outside, the inner lip continuous : aperture much broader than high, transversely auriculate, narrowing inwards |