OCR Text |
Show 148 DR. O. F. VON MOELLENDORFF ON [Feb. 20, artificial division of the genus as given by Pfeiffer they might classed in Discartemon. 4. STREPTAXIS (OOPHANA) BULBULUS, Morelet. Streptaxis (Oophana) Indbulus, Tryon, Man. Pulm. i. p. 80, 1.15. figs. 41-43. Described from Pulo Condor. The single specimen from the Samui group is rather more ventricose, the dimensions being 15 : 11-5 millim. instead of 16-5: 11 in the type. 5. STREPTAXIS (OOPHANA) STRANGULATUS, sp. nov. (Plate XVI. fig. 5.) T. aperte umbilicata, ovata, sat tenuis, subtiliter arcuatim costulata, sericina, hyalina; spira subregulariter ventroso-conica, obtuso, glabrato. Anfr. 6, sat convexi ; ultimuspaullum devians, circa umbilicum compressus, obtuse carinatus, pone aperturam subito coarctatus. Apertura parum obliqua, truncato-ovalis; peristoma late expansum, tenue, intus callosum, ad insertionem marginis externi attenuatum. Lamella parietalis valida, elevata; dentibus 5, uno in parte superiore collumellce, 2 margine basali, 2 in margine externo oppositis. Alt. lOp5, diam. 7"5 millim. Although certainly belonging to the group of the last species, this peculiar form differs at once in the almost regular, hardly deviating last whorl and the peculiar coarctation behind the mouth, which calls to mind the similar formation in certain species of Alycceus (Dioryx). The whorls also are more convex, the shell is thinner, the peristome broader, and there are 5 teeth instead of 3. Mr. Ancey is quite right in considering his group Oophana, of which S. bulbulus is the type, to be a connecting-link between Streptaxis and Ennea. In fact /S. strangulatus would at first sight rather be considered as an Ennea by many, on account of its regular shape. That this is, however, a Streptaxis and not an Ennea may be inferred from young specimens, which showr no teeth, whilst all the young Ennece are dentate. Fam. NANINID^E. 6. MACROCHLAMYS LIMBATA, sp. nov. (Plate XVI. figs. 6, 7.) T. perforata, discoideo-depressa, solidula, subtiliter striatula, spiralibus nullis, 'pellucida, nitens, pallide corneo-flavescens, subregulariter corneo-strigata. Anfr. 6, convexiusculi, lente sutura profunda marginata discreti; ultimus descendens, basi convexior, circa umbilicum excavatus. Apertura fere verticalis, late elliptica, valde excisa; peristoma rectum, acutum, margine columellari leviter refiexo, intus lafiuscido, sat crasso limbatum. Diam. maj. 19-22-5, min. 16-5-20, alt. 10-25-13-5 millim. |