546 Records of the Indian Museum. [Vol. XXII, 



ViVIPARAE OXYTROPIDES. 



Vivipara microchaetophora, sp. nov. 



1S77. Paliiilina bengalensis vav. cingtilata {\\\ part), Nevill, Cat. Moll. 



Ind. Mas. E, p. 29. 

 18S5. Paliidijia bengalensis subsp. cingiilata. subvar. Nevill Hand 



List Moil- Ind. II, p. 22. 



Although this species was not found in Manipur it may be con- 

 veniently described here as it has a distinct bearing on the origin 

 of V. oxytropis, one of the most characteristic of the Manipur 

 molluscs. 



The shell is small, thin, sharply acuminate, somewhat elongate 

 and imperforate. It is divided into two regions bj^ a blunt peri- 

 pheral ridge on the body-whorl, above which it is narrowly conical, 

 while below it is broad and rounded. There are 5f whorls. Those 

 of the spire are very slightly convex but obliquely and not very 

 broadly flattened above. The suture between them is not strongly 

 impressed except sometimes in old shells above llie bodj^-whorl, 

 and they increase in size gradually and evenlj-. The body-whorl 

 19. more swollen but transverse and less than twice as deep on the 

 outer as on the inner margin. The aperture is of moderate size, 

 subrhomboidal, rather narrow, higher than broad, pointed above 

 and often subangulate below, slightly oblique. The peristome is 

 complete, the outer lip sharp, the columella strongly arched, with 

 its fold narrow and bj' no means prominent. The region to the 

 left of the mouth in the natural position of the shell slopes up- 

 wards somewhat abruptly and is very slightly convex. In young 

 adult shells the colour is a translucent olivaceous j^ellow, as a rule 

 tinged with green on the body-whorl. The apical whorl and a 

 half are dull purple and the others are marked with numerous fine 

 spiral bands of the same colour. The suture is also deeply tinged 

 with purple. The inside of the shell is white and the peristome is 

 linearly edged with black. In old shells the distinctive colouration 

 is apt to be obscured by a general blackening of the surface and 

 this sometimes occurs in quite small specimens. On the body- 

 whorl there is not as a rule any very definite trace of thickened 

 spiral ridges, except for the peripheral keel, but sometimes the 

 dark bands are a little thickened. On the whorls of the spire, 

 however, at least two fine spiral ridges can as a rule be detected 

 with the aid of a hand lens, while in the embryo there are several 

 and even in the adult more than two can be discovered under a high 

 power of the microscope. All these ridges are punctate and when 

 the shell is fresh bear rows of minute chaetae-like processes of the 

 periostracum. The processes are, however, so delicate that thej' 

 usually disappear as the sheH dries. 



The embryonic shell differs from that of any form of V . ben- 

 galensis in its broader, more conical form, in the produced charac- 

 ter of the apical whorl and a half and in the very strong peripher- 

 al keel of the body- whorl. 



The operculum is very thin and of a pale golden brown colour. 



