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Show 1895.] BOBNEO AND NEIGHBOUBING ISLANDS. 103 angulato-lunata, obliqua; peristoma tenuissimum, margine columellari supra umbilicum breviter reflexo. Diam. maj. 29 millim., min. 26*5, alt. 16. Hab. Mount Eabong in the south-western part of Sarawak. This species, which may possibly be a dextral Dyakia, is quite distinct from H. elensa or H. egeria. It has a more raised spire than the latter, is more strongly sculptured both above and beneath, and is less glossy upon the under surface. H. elensa is more widely umbilicated, is differently sculptured, and has much more rapidly enlarging whorls, which also, in shells of the same dimensions, are fewer in number. 8. DYAKIA LINDSTEDTI (Pfeiffer). (Plate II. fig. 10.) Helix lindstedti, Pfr. Proc. Zool. Soc. 1856, p. 387; M o n . Hel. vol. iv. p. 31. Hab. Malacca (Pfr.); Penrisen Mountain, Sarawak, up to 3500 „ feet (A. Everett). T w o varieties were collected at the above locality by M r . Everett. Both are represented by dextral and sinistral specimens, the latter appearing to be the more common form. The rate of growth in all of these specimens is imperceptibly slower than in the type of the species, so that the last whorl is very slightly narrower. One of the varieties is of the same uniform pale greenish horn colour as the type ; the other (var. castanea) of a rich brown tint, excepting the keel and suture, which are yellowish. This may be Nanina janus (Chemn.), as identified by Dr. E. von Martens (Preuss. Exped. Ost-Asien, Zool. vol. ii. p. 226, pi. xi. fig. 4). The sculpture is precisely similar in all. This species approaches very closely to D. regalis in form and sculpture, but it does not exhibit the plications at the upper part of the spire which are characteristic of that species. D. regalis, however, which is variable in colour, is usually rather smaller; the basal portion of the latter around the umbilicus is of an opaque creamy tint. A somewhat similar pale zone exists in the type of D. lindstedti and is also faintly indicated in some of the Penrisen shells. Probably tbe two species pass imperceptibly one into the other. The shell figured is the type specimen described by Pfeiffer from Malacca. 9. DYAKIA BUSANENSIS, G-odwin-Austen, var. Dyakia busanensis, G.-A. Proc. Zool. Soc. 1891, p. 31, pi. ii. fig.l. Hab. Batang Lupar district, Sarawak. The specimens from this locality differ from the typical form in being of a uniforn horny brown colour (var. concolor). The spire may be a trifle less conical, but as regards the number of whorls vand the character of the sculpture they are practically identical. The whorls are a trifle convex and distinctly impressed above the |
