| OCR Text |
Show 1895.] BOBNEO AND NEIGHBOUEING ISLANDS. 101 rotundatus, haud descendens ; apertura oblique lunata ; peristoma tenue, margine columellari superne breviter et anguste reflexo. Diam. maj. 18 millim., min. 16, alt. 12. Hab. Upper Padas, British North Borneo. A transparent, glossy, narrowly perforated shell, without colour-markings, and with only very faint lines of growth, and here and there very feeble indications of spiral striation. A dark line, occasioned by stains from the animal and which can be washed away, frequently accompanies the suture. 3. XESTA THISBE. (Plate II. fig. 4.) Testa subglobosa, conoidea, perforata, ad peripheriam subangulata, rufo-cornea, zona angusta pallida, supra rufo-fusco marginata circa medium cincta, polita ; spira convexe conica, ad apicem mediocriter acuta; anfractus 6, convexiusculi, striis incrementi tenuissimis sculpti, idtimus supra et infra medium subcequaliter convexus, ad peripheriam obtuse angulatus; apertura obliqua, irregulariter lunata ; peristoma tenuissimum, margine columellari supra umbilicum breviter dilatato, reflexo, purpureo. Diam. maj. 26 millim., min. 23, alt. 18. Hab. Mount Eabong, in the south-wrestern part of Sarawak. Differing from X. de crespignii in colour, the more angular body-whorl, and more slowly increasing spire. The periphery is marked by a pale yellow narrow zone, and the rich brown band, which is contiguous with it above, revolves up the spire a short distance. The surface is highly glossy, and, in addition to the delicate lines of growth, faint indications of very fine spiral striation are here and there traceable. In certain positions the incremental striae beneath the suture appear more distinct than upon the rest of the surface. 4. HEMIPLECTA DENSA (Adams & Eeeve), var. EVEBETTI. (Plate II. fig. 8.) In the 'Annals,' 1893, vol. xi. pp. 349, 350, I mentioned the occurrence at Palawan of a very acutely keeled variety of this species. It most nearly resembles that form which is recognized as var. Schumacheriana. It is, however, a trifle larger and flatter above, the peripheral keel in consequence appearing somewhat more acute. Additional specimens brought by Mr. Everett appear to make it advisable to designate it with a varietal name. I would therefore suggest that it be known as var. everetti. The largest example from the south-eastern part of the island is 58 millim. in diameter. 5. HEMIPLECTA PE;ECULTA. (Plate II. fig. 7.) Testa anguste umbilieata, depresse conica, ad peripheriam acute carinata, mediocriter tenuis, subpellucida, cornea, epidermide pallide olivacea induta, infra suturam et peripheriam pedlide vel saturate rufo-nigro marginata ; spira breviter conica ; anfractus 5-6, celeriter accrescentes, superne vix convexiusculi, inferne |
