1921.] N. Annandale & B. Pkashad : Indian Molluscs. 133 



These differences, in our opinion, are not sufficient for separating 

 this single shell as a distinct species or variety. 



As already noted the species is known only from a place at 

 least 200 miles above the extreme tidal lim[t. 



Stenothyra puncticulata (Gould). 



1S47. tVemuftii-d Miiictiriildtn. ('nuild, Pi-oc. Bostnii Soc. Nat. Hist. 



II, p. 221). 

 1S76. StenotJivrn pn iictinilntn. Tlicohald, op. cit., p. 15. 



Gould described this species from specimens sent to him from 

 Tavoy, Burma. He stated that the species was of the shape and 

 size of deltae, but had the aperture much more distorted ; there 

 was no umbilicus and the shell had a characteristic sculpture. 



Nevill doubtfully considered it to be a synonym of 5. momli- 

 fera. We have seen no specimens and it is not possible to be 

 definite about it from the description only. We, therefore, hesi- 

 tate in accepting Nevill' s suggestion. Should, however, the two 

 pt-fve to be synonymous, then the name of the species must be S. 

 puncticulata with S. nionihfcra as a synonj'm, and a new name will 

 probably have to be given to S. puncticulata, .\dams,' from the 

 ' Eastern Islands, ' 



Subgenus Astcnothyra, nov. 



1S80. Hydrobia [Belgraudia). Nevill, op. cit., p. 161. 

 1881. Hydyobia {Belgraudia), Nevill, op. cit., p. 158. 

 1885. Hydrobia {Bythinellii), in pt., Nevill, op. cit., p. 49. 

 1915. Bitliinella, Preston [nee Moquin-Tindon), op. cit., p. 66. 

 1915. Paludina {Belgraudia), Preston [nee d'Orbigny and Bourguig- 

 nat), lb., id., p. 67. 



The shell is of more normal Hydrobiid facies in the dorsal 

 and ventral aspects than in Stenothyra {s.s.) ; the surfaces of the 

 body- whorl being convex, and the aperture being larger, slightly 

 prominent and of ovate form. There is no definite triangular 

 area between it and the outer edge of the body- whorl. The oper- 

 culum naturally corresponds in outline with the aperture, but 

 agrees in structure with that of Stenothyra [s.s.) and we have not 

 discovered any difference in the radula or soft parts, except that 

 the foot is not produced posteriorly. 



Type-species. — Hvdrobia (Belgrandia) miliacea, Nevill. 



We recognize two species of this subgenus, (i) A. miliacea 

 (Nevill), and (ii) .4. burmanica, nov. ; of the former we are able to 

 distinguish three varieties (i) jorma typica, (ii) var. subangulata , 

 and (iii) var. gibbosula. These species and varieties may be distin- 

 guished with the help of the following key:— 



1. Shell elongale-conic.il, soniewlial iiirreted with a very 



long spire and having a smooth shell ... ... A. miliacea. 



.\. Bod)-\vhorl with a distinct keel ... var. gibbosula. 



B. Body-whorl sinooth. 



/. ."KperUre evenly rounded . ... forma typica. 



II. Aperture subangulate .. ... ... \Ar. subangulata. 



' Adams, Proc. Zool Soc. London, p. 226 (1851'). 



