1918.] N. Annandale : Molluscs of the Inle Lake. 123 



with the whorls swollen in both planes and the suture impressed, 

 narrowly umbilicate ; aperture large, broadly sub-oval, rounded both 

 in front and behind, strongly rimate and projecting ; lip thin, sharp ; 

 columella arched. 



Measurements of specimen. 



mm. 

 Length of shell ... ... ... ... ... 3 



Breadth of shell ... ... ... ... ... 2 



Length of aperture ... ... ... ... 1-5 



Greatest breadth of aperture ... ... ... ... 1 



The operculum is ovoid, pointed posteriorly, broadly rounded or 

 sub-truncate anteriorly ; it is thick but hyaline ; 4 whorls can be dis- 

 tinguished on it ; the outer surface is nearly flat ; numerous spiral striae 

 run round its periphery ; the inner surface, which has a peripheral 

 ridge, is strongly convex. Towards the periphery the suture becomes 

 merely a ridge on the inner surface. 



Type- specimen. No. M. 11110/2, Zoological Survey of India 

 {Ind. Mus.). 



The species is probably allied to A. cincla, Gould, from Tenasserim, 

 but differs in that the body- whorl of the shell is not subcarinate. From 

 A. parvula (Hutton) the shell may be at once distinguished by the 

 broader whorls of its spire. Moreover, A. parvula is stated to have 

 a horny operculum. 



This species is not uncommon in the Inle Lake, in which it occurs 

 both in the central region and the marginal zone, always among living 

 weeds. We found several subfossil shells on the banks of the He-Ho 

 stream. They did not differ from fresh specimens. 



Family VI VIP ARID AE. 



Genus Vivipara, Lamarck. 



It is a remarkable fact that only a single specimen that can be 

 assigned to any normal species of this almost universally distributed 

 genus was found in the course of our tour in the Southern Shan States. 



Vivipara lecythis (Benson). 



183G. Paliidina Lecythis, Benson, op. rit., p. 745. 



1876. Paludina lecythis, Hanley and Theobald, op. cit., pi. Ixxvi, fig. 6. 

 1909. Viviijara leci/this, Kobelt, Paludinen m Martm and Chemnitz, Conch. Cab., 

 p. 148, pi. 30, figs. 1, 2. 



Specimens of this species from different localities differ considerably, 

 but as we obtained only a single broken shell in the Inle Lake, it is 

 impossible to describe the local race it probably represents. 



The shell was found floating on the surface of the water in the mar- 

 ginal zone close to the western shore of the lake. 



Genus Taia, gen. no v. 



I have thought it necessary to give a new generic name to a group 

 of Viviparidae that seems to be peculiar to the Shan Plateau and Upper 



