1881.] Mollusca of tie Lido-Malayan Fauna. 165 



drate, no basal emargination, outer lip very much thickened, not dilated, 

 evenly rounded at base. 



Long. 5^, diam. 2 mil. 



Rare, in sand from Roweiah, Red Sea. 



Type, Indian Museum. 



This species discovered by my friend Mr. J. B. Baxter, is an inter- 

 esting addition to the group II, section B. of Schwartz, which I now pro- 

 pose to distinguish by the name of Schivartziella, at once recognizable by 

 the absence of any basal emargination within the aperture. The differences 

 from true R. bryerea, as can be seen from the above, are too many and too 

 marked to require special, further reference ; but it becomes a question 

 whether Schwartz's above quoted fig. A represents or not the present 

 species ? I am inclined to believe from the acute peristome &c, that it 

 represents a not adult specimen, readily distinguished by the different shape, 

 transverse striation, less numerous ribs &c. from JR. bryerea. The most 

 important difference in it from the Roweiah form is the absence of the 

 basal three transverse ribs and corresponding abrupt termination of the 

 longitudinal ribs ; these latter are also thicker, straighter &c, the peristome 

 much broader and aperture smaller. 



AMPHTTHALMUS PELLY.E, n. sp. 



Of almost microscopic size, imperforate, solid, smooth, polished and 

 shining, of a rich chesnut-brown colour, ovately oblong; spire shortly and 

 ventricosely conical, suture distinct, apex exceedingly obtuse ; whorls 3f, 

 very convex, last whorl produced, regularly ovate, about f the size of the 

 whole shell, brought forward at the aperture in a highly characteristic 

 manner, exactly as in the genus Stenothyra ; aperture almost circular, with 

 continuous and much thickened margins, stained of a very dark mahogany 

 colour within the aperture, behind the peristome there is a " rib-like" 

 thickening, showing through externally in an opaque manner. 



Long. 1\, diam. \ mil. 



In sand, from near Adelaide, South Australia. 



Type, Indian Museum. 



This very interesting minute form, of a little known genus, I have 

 named after its discoverer, Miss Pelly, to whom I am indebted for the type 

 specimen. The other shells found with it were all of a purely marine type, 

 there being no brackish-water forms amongst them. Barleeia (? ) microthy- 

 ra, Martens, Mobius Reise &c, PI. XX, fig. 18, from Mauritius is another 

 and most closely allied species of Amphithalmus ; A pellyce is readily 

 distinguished by the fewer whorls, more obtuse apex, more convex whorls, 

 the last especially being much more regularly, ovately produced and much 

 longer in proportion, its Stenothyra-\ike deflection in front of the aperture, 

 22 



