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Show 314 LIEUT.-COL. H. H. GODWIN-AUSTEN ON [June 18, margin at right angles to the bodv-whorl, and at last forming a flat brnad wing, with a shallow fold near the suture. Size: maj. diam. 28*75, min. 21*25; alt. axis 6*5 millim. Operculum shelly in front, multispiral, having the appearance of a strand of rope coiled on itself, thin, flat, and horny on the inner side. Hab. Molu Hills (R. Hungerford). 31. CYCLOTUS TRUSANENSIS, n. sp. (Plate XXXVI. figs. 5, 5a.) Shell discoid, very widely umbilicated ; all the whorls showing; sculpture a thick epidermis, with lines of growth ; colour dark umber-brown, with a few small splashings of cchre ; spire flatly depressed ; apex scarcely rising above the last whorl; suture impressed ; whorls 5, rounded, the last slightly descending ; aperture circular, oblique; peristome double, inner simple, continuous, tbe outer slightly reflected, gradually expanding towards the margin, forming at the suture a small wing, which is attached to the penultimate whorl. Size (of shell drawn): maj. diam. 18*5, min. 150 ; alt. axis 4*5; diam. aperture 7*80 millim. Size (largest in collection): maj. diam. 22*5,min. 17*5; alt. axis 5*0; diam. aperture 9 0 millim. Operculum shelly in front, flatly concave, with a small central circular depression, horny at back, surface flat. Hab. Trusan Island (A. Everett). This shell without its operculum might on a casual examination be referred to Pterocyclos tenuilabiatus, Metcalfe; but it may be distinguished from this latter by its closer umbilication and by the last whorl not descending so rapidly. It is remarkable to find two shells so very similar, and yet showing so wide a difference in the form of the operculum. Pterocyclos tenuilabiatus is quite plain in coloration, while Cyclotus trusanensis shows bands of pale zigzag markings. 2nd Group. Cycloti marmorati. Shell more or less turbinate, narrowly umbilicate, smooth, with marbled or fine zigzag markings. Cyclotus amboinensis, Pfr. Cyclophorus amboinensis, Pfr. P. Z. S. 1852, p. 144. Cyclotus amboinensis, von Martens, Preuss. Exped. Ost-Asien, p. 121, pi. ii. figs. 4. 5. Hab. Borneo. In Cuming collection, Brit. Mus. This locality is doubtful ; von Martens gives it from the Moluccas only, Amboina, Buru, &c. 3rd Group. Cycloti suturales. Turbinate shells, openly umbilicate, plain in coloration, the last whorl slightly separated from the antepenultimate. Peristome simple, not reflected at all. |