OCR Text |
Show 1881. SHELLS FROM SOCOTRA. 255 OTOPOMA CLATHRATULUM, var. MINOR. ;Miell closely umbilicated, very globosely turbinate, solid, polished, M ulpture regular spiral ribbing, crossed by fine transverse irregular costulation; colour white, one specimen dark grey on the apex ; spire conoid, apex blunt, and smooth for 1| whorl; whorls 4|; aperture ovate ; peristome simple, strong, and attached close to the penultimate whorl. Operculum situated close to the peristome, very thick and shelly, the subcentral nucleus slightly sunken below the outer whorl; dark grey in central portion. Size:- Major diam. 0'54, minor diam. 0#40, alt. axis 0*40 inch. „ 18-0 „ „ 15-3, „ „ 16-6 millims. 'ain near Gollonsir village, very common." (I. B. B.) The °r, however, are marked " very common, from the plain | "adhab."] ry similar to the last, but only about half the size; '*! the position of the peristome with respect to .yery marked and constant. 'Plate XXVIII. fig. 1.) •solid; sculpture fine, regularly ^ulation, continued to well ;re conic, sides rather ^ 5, the last well oblique; peri- Operculum nucleus ^ |