OCR Text |
Show 1899.] GENERA STREPTAXIS AND ENNEA. 767 the last whorl. There are some faint impressed spiral lines on more than one of the Kolamalai specimens. The Torna specimen has only one parietal lamella and five palatal teeth, two being columellar. It should perhaps be classed as distinct. STREPTAXIS SUBACUTUS, sp. nov. (Plate L. figs. 1, 2, 3.) Testa arcuatim rimato-perforata, depresso-ovata, solida, flcxuose costulato-striata, subtus laevigata ; spira depresso-conoidea, acutiusculo ; anfr. 6k, planulati, penultimus ad peripheriam obtuse carinatus, dimidio latitudinis ultra anfractum ultimum projectus, ultimus valde excentricus, subtus convexiusculus, circa umbilicum versus aperturam angulatus, in umbilico rugoso-striatus, post aperturam fossiculo longitudinali subbasali impressus; apertura subdiagonalis, fere semiovalis, lamellis duobus parietalibus, und longiore media, altera juxta angulum brevi, tribus-que dentibus palatalibus, uno clextrali, secundo basali, tertio columellari, coarctata; peristoma expansum, margine dextrali ad angulum sinuato. Diam. maj. llg, min. 8; alt. 6 mm. Hab. South Canara (Beddome). This is the third and largest species of carinate Streptaxis from Southern India, the two others being S. canaricus and S. compressus. These three species bring up the number of forms described from Southern India to eleven. Owing to the considerable amount of variation, especially in the teeth within the aperture, as already noticed, it is very difficult to make a key to these, but they may generally be identified by the following :-• A. Penultimate whorl rounded at periphery. a. Parietal larnellas 1 or 2, not Y"SQaPe(L n o r joined to margin of peristome by raised callus. a. Shell above smooth or slightly striated. a'. Penultimate whorl projecting on lower surface beyond last whorl. a2. T w o parietal lamella; (one sometimes in S. per~ rotteti). a3. Length 8-10 m m . ; usually 3 palatal teeth... *S. perrotteti. b3. Length 6j m m . ; 1 or 2 palatal teeth S.jootei. c3. Length 6 m m . ; 3 to 5 palatal teeth S. watsoni. b2. A single parietal lamella; length 6-7 m m 8. beddomii. b'. Penultimate concealed by last whorl beneath 8. concinnus, b. Shell costulately striated above 8. scalptus. b. A single Y-SDaPe(l parietal lamella, arising from raised callus that unites margins of peristome. a. Smooth; lower surface of penultimate whorl scarcely projecting S. personatus. b. Costulate ; half of penultimate whorl projecting S. promts. B. Penultimate whorl keeled. a. Costulate. a. Length about H i m m . ; 3 palatal teeth S. subacutus. b. Length about li m m . ; 6 palatal teeth S. canaricus. b. Smooth or striated ; 4 or 5 palatal teeth S. compressus. |