BY DR. J. c. COX. 567 



Bulimus (Placostylus) hobsoni, n.sp. 



(PI. xx. ? figs. 2 and 3.) 



Shell deeply and openly rim ate, comparatively thin and light 

 for its size, translucent, the sculpture and markings are very 

 visible on the body whorl through the wall of the shell by trans- 

 mitted light ; shining and lustrous, of a light reddish-brown 

 colour, the whorls of the spire becoming lighter in shade and 

 more of a pinkish-brown ; ornamented with many irregularly 

 sized and irregularly distributed chestnut-coloured tentoriform 

 markings ; whorls slightly inflated, causing the suture to assume 

 an impressed character. Suture margined by a narrow opaque 

 slightly raised knotted selvaged margin (not smooth and straight 

 as represented in the figures) ; whorls longitudinally irregularly 

 marked with lines of growth and transversely subcostately ridged 

 with rather coarse raised undulating lines, which frequently anas- 

 tomose (a character quite omitted in the figures, but which is very 

 characteristic), becoming much less distinct on the whorls beyond 

 the body whorl, till, on the third whorl from it, they are almost 

 invisible, and are gradually replaced by a granular punctation, 

 which increases in distinctness quite to the apex • these granular 

 punctures are disposed in two distinct transverse slanting rows, 

 one running from right to left, the other from left to right. 

 Aperture oblong-ovate, of a pinkish-brown colour; peristome only 

 slightly thickened and everted, pinkish-brown throughout, except 

 at the columella which is of an opaque white only very faintly 

 tinged with pink-brown ; columella broadly expanded and dividing 

 at its insertion, as in all the shells of this group, into two processes, 

 the outer and smallest gradually blending with a thin transparent 

 glassy callus, which runs towards the insertion of the upper end of 

 the peristome, which is rather arched out from the side of the 

 shell as it leaves its insertion (more so than is represented in the 

 figure), the larger process of the divided columella enters spirally 

 the interior of the shell. In the several specimens of this species 

 which I have seen, there is no disposition to the formation of a 



