OCR Text |
Show 1881.] SUMATRA AND BORNEO. 633 33. CORBICULA GRACILIS, Prime. Abundant in all the lakes in Sumatra, especially Lake Singkarah. The shell is fished in quantities, and used for making lime for betel-chewing. 34. UNIO DIMOTUS, Lea. Abundant. II. Shells collected in Koetei and in the Amontai and Bandjermasin Districts of Borneo. HELICIDAE. 1. N A N I N A (RHYSSOTA) BROOKEI, Adams & Reeve. I found dead specimens in Koetei. The Dyaks use them as ornaments in the top of the lids of their arrow-cases. Six live specimens at Mindai (in Amontai district). It is, however, rare, hiding in layers of decayed leaves. 2. NANINA (XESTA) CONSUL, Pfeiffer. Found at Mindai. Two specimens. 3. HELIX MINDAIENSIS, nov. sp. (Plate LV. fig. 7.) Shell very slightly umbilicated, sinistral, convexly conoid, semi-transparent, of a reddish brown colour, with a white-tipped lip. Spire conical, with somewhat convex outlines and the apex obtuse. Whorls 6, but slightly convex, sculptured with finely granulated radiating strise, regularly increasing ; the last acutely keeled. Aperture oblique, lunate. Peristome sharp, slightly thickened; upper margin short, oblique, the basal (seen from beneath) rather sinuous. Greatest diam. 30 millim., axis 13 millim. HaB. Mindai (Amontai district), very abundant amongst the decaying leaves in the forest. This species is of a darker colour than Helix maarseveeni, has one whorl less, has more convex outlines to the spire, is not so sharply keeled around the last whorl, and more narrowly umbilicated. Its sculpture, too, is rather more coarsely granular. 4. HELIX (VIDENA) METCALFEI, Pfeiffer. One specimen, collected at Mindai. 5. HELIX (VIDENA) PLANORBIS, Lesson. From Mindai. Scarce. 6. BULIMUS (AMPHIDROMUS) INTERRUPTUS, Muller. This shell was very abundant in Bandjermasin, both the dextral and sinistral forms, and variously coloured ; of the rare pure white variety only one specimen was obtained. After heavy rains the trees were quite spotted with them. PROC. ZOOL. Soc-1881, No. XLI. 41 |