1805.] Contributions to Indian Malacology. 85 



Genus DIPLOMMATINA. 



28. D. nana, n. sp. 



Shell not riinate, dextrorse, subovate, rather solid, amber-coloured, 

 very finely and closely filiformly costulatecl on the lower whorls, less 

 closely on the upper, or, frequently, subdistantly costulated through- 

 out. Spire conical, with sides scarcely convex above ; apex rather 

 obtuse, sometimes reddish, suture impressed. Whorls 6 — 6|, rounded, 

 antepenultimate the largest, the last rising considerably upon the 

 penultimate. Aperture vertical, ear-shaped, nearly circular, columellar 

 margin straight for a short distance and vertical, with an internal 

 tooth. Peristome double, both portions expanded and appressed, the 

 inner forming a thin callus upon the penultimate whorl. Operculum ? 



Millem. inch. 



Length, 21 0.09 



Diameter, 1 0.04 



Aperture with peristome about § millem. in diameter. 



Habitat — Akoutoung, Thondoung and Yenandoung in Henzada 

 district, Pegu. 



This species approaches D. polypleuris, Bens., more nearly than 

 any other. It is distinguished by its more regularly ovate form, 

 blunter apex, less swollen penultimate whorl, and more marked and 

 distant sculpture. The latter character, however, varies. The 

 specimens from Thondoung, a hill about 20 miles south of Akoutoung, 

 being either closely costulate throughout, or subdistantly sculptured 

 above, closely below ; while in Akoutoung specimens, the costulation 

 is subdistant throughout. As, however, I can trace no other distinc- 

 tion between the shells, and the costulation varies in different indivi- 

 duals from each place, I do not think there is any specific distinction. 



A still more minute species than the present exists in Pegu, and 

 I found two dead specimens at the base of the Arakan hills in the 

 Henzada district. As these specimens were not very well preserved, 

 I abstain from describing them for the present. 



Family Helicinidas. 

 Genus HELICINA. 



29. H. Arakanensis. 

 Shell depressly turbinate, sublenticular, rather thin, obliquely striated 

 above, radiately and very minutely beneath, polished, nesh-coloured, 

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