154 G. Nevill— New or little-known [No. 3, 



Type, Indian Museum ; subf ossil, at about \ of the ascent of the Pouce 

 Mn., Mauritius. 



This shell was a contemporary of the subfossil Cyclostoma caldwellia- 

 num, Nev., 0. scabrum, H. Ad., C. mauritianum, H. Ad. &c, which I found 

 associated with it, some few inches below the surface of the soil and gener- 

 ally more or less under overhanging large blocks of stones. It is doubtless 

 a remnant of the old fauna of the island and must be at least as old as 

 the Dodo. It is a very important species, as showing one of the characters 

 of the genus (from which indeed its name is derived) in its greatest develop- 

 ment so far as is yet known ; I allude to the keel round the umbilicus. I 

 have named it in honour of my friend Mr. Evenor Dupont of Mauritius, 

 who is well known for his many discoveries in Natural History in those 

 parts. We now know that the genera Cyclostoma, Omphalotropis, Heli- 

 cina, Gibbus, and Nanina are all very ancient inhabitants of the Mascarene 

 Islands, as extinct subfossil forms of all of them have been described. 

 Helicina appears to have died out. 



Omphaloteopis caldwelliana, n. sp. PL VI, Fig. 9. 



Hand-list I, 1878, p. 320, No. 7, as Omphalotropis, n. sp. 



Distinctly umbilicate, rather solid, colourless and without sculpture, 

 pyramidically conical ; spire elongately turreted, apex rather acute, suture 

 subcanaliculate ; whorls 7, planulate, increasing very slowly and regularly, 

 the last one short, tumidly ventricose, perfectly rounded at the periphery, 

 umbilicus surrounded with a raised and prominent keel ; aperture slightly 

 oblique, narrowed anteriorly, margins not continuous, peristome slightly 

 convex only, columellar margin anteriorly inflected, in the middle suban- 

 gulate, then rounded and again subangulate quite at the base. 



Long. 6, diam. 3 mil. 



Type, Indian Museum. 



Subfossil, on the ascent of the Pouce Mn., Mauritius, with O. dupon- 

 tiana, &c. I have named this species after Mr. J. Caldwell of the Colonial 

 Civil Service, the possessor of one of the finest collections of shells from 

 our Eastern Eegions that I know of. In shape there is some resemblance 

 to the O. clavulus of Morelet, which is not mentioned in Pfeiffer's 

 monograph ! 



Omphaloteopis eube^s, Quoy, PI. VII, Fig. 12 (Copy). 



Voy. Astrpl. 1832, Mauritius. 



I have thought it well to give a copy of the animal of this genus, 

 taken from Adams' ' Genera,' to enable those interested to see at a glance 

 the great differences from that of Assiminea, as the shells of the two 

 genera are constantly confounded, since Dr. Pfeiffer unfortunately united 

 them as ' Hydrocena* 



