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Show 1881.] SUMATRA AND BORNEO. 629 becoming pinkish grey at the apex, narrowly umbilicated, whorls 6, oblique arcuate, sculptured with lines of growth and concentric finely granular striae, producing a shagreened appearance, especially on the last whorl, which is also considerably wrinkled, and bears a somewhat raised ridge or keel at the periphery, which, however, does not produce an angle, not descending in front. Whorls of the spire only a little convex, the last large, rather ventricose. Spire shortly conical, with the apex obtuse. Aperture large, broadly obliquely lunate, of a somewhat mauve tint within. Peristome thin, simple, only very shortly expanded over the umbilicus. Hab. Mount Sago, at an elevation of 2000 feet, only one specimen found, in a decayed trunk. Like the rest of the Nanina? I found in Sumatra and Borneo, this also is sinistral. Greatest diameter 40 millim., height 31 millim. 7. HELIX (NANINA) MAARSEVEENI, sp. nov. (Plate LV. fig. 2.) Shell perforate, sinistral, depressedly trochiform, thick, of a light brown horn-colour, somewhat paler round the umbilicated region. Spire conically depressed, with the apex obtuse. Whorls 7, sculptured with feebly granulated, obliquely arcuate lines of growth, and increasing slowly; last whorl with a very acute pale keel about the middle, below the carina rather concave than convex, sculptured like the upper surface, the lines being rather flexuous. Aperture oblique, angularly lunate. Peristome thick ; upper margin above the keel short, oblique, rectilinear, the basal very arcuate, towards perforation somewhat expanded. Greatest diameter 33 millim., axis 14 millim. Hab. Sidjoendjoeng. I have associated the name of Mr. Maar-seveen (the Assistant Resident at Sidjoendjoeng) with this shell, of which I only found three specimens. A near ally in form and colour is II. hugonis, Pfr., from La-buan; but H. maarseveeni has an extra whorl, is umbilicated, and the spire is considerably less elevated; and the granular sculpture in H. hugonis is much stronger. H. maarseveeni comes much nearer Helix mindaiensis, found by me in Borneo; but that has only six whorls. 8. HELIX SMITHI, sp. nov. (Plate LV. fig. 3.) Shell thin, orbicular, umbilicated, flatly depressed, semitrans-parent, of a greyish white colour, covered with a thin epidermis of a light horn-colour, spire flattened. Whorls 4, flattish, sculptured with fine lines of growth, the last slightly descending at the mouth, broad, with a strongly marked obtuse keel, and a broad distinct groove above, below convex, obtusely ridged round the deep umbilicus. Aperture large, subquadrangular, oblique. Peristome thin ; outer margin expanded, reflexed, especially in the umbilical region. Greatest diameter across 21 millim., height 8 millim. Hab. Paio, Sumatra. Two specimens found (only 1 adult). Helix smithi is nearly allied to H. caseus, Pfr., from Siam; but the latter differs in having a less acute keel on the last whorl, |