BLANFORD : LAND AND FRESH-WATER MOLLUSCA FROM SIAM. 281 
the aperture, and the forms of Pterocyclus inhabiting the countries 
to the east of the Bay of Bengal. P. Mariont, Ancey (Bull. Mus. 
Marseille, i, 1898, p. 137, pl. ix, fig. F), is a typical Ahzostoma, 
near P. Houset, with which it has been united by Dautzenberg. 
[‘‘ Not common. Found on rocks only.”—W. M. D. | 
23. Rutostoma Datyr, BIf. Proc. Malac. Soc., ante, 1902, p. 34. 
This is perhaps only a variety of 2. Haines: (Pfr.). 
[‘*Not common. Only taken at Pitsunaloke in one locality, in very 
dark and dense forest.” —W. M. D. ] 
24. Purina artata, Bens. Lampun. 
The four shells sent appear to me to agree very fairly with typical 
Moulmein specimens. I doubt whether the common Pegu form 
(the identity of which with the real P. Peguensis, Bens., is open to 
grave doubt) can be distinguished from P. artata. This subject has 
been discussed by Colonel Godwin-Austen (Land & F. W. Moll. India, 
vol. i, pp. 34-41). 
[‘‘ Very rare. I only got seven shells after hunting in different 
places for many days.”—W. M. D. | 
Family VIVIPARID 2. 
25. Vrvrpara crnevtaTta, v. Mart. Lampun. 
This is regarded by Nevill (Handlist Moll. Ind. Mus., vol. 11, p. 22) 
as a subspecies of V. Bengalensis, Lam., probably with justice. 
[‘* Very common. Eaten by the Laos. On 15th October cleaned 
fifteen specimens, and all were full of young.”—W. M. D. | 
26. Vivipara TRocHOIDES, v. Mart. Lampun and Pitsunaloke. 
[ ‘‘ Common in swamps and open marshy land.”—W. M. D. | 
27. Vivreara Eyrtest, Morelet. 
The only specimen received came with shells from Pitsunaloke, and 
is probably from that neighbourhood. 
Family AMPULLARIID &. 
28. AmpuLtarrA pourra, Desh. 
A typical specimen without exact locality. 
29. AmpuLLaRIa conica, Gray. Pitsunaloke ; Lampun. 
30. AMPULLARIA GRACILIs, Lea. Lampun. 
[‘‘ Very common, and often found for many miles inland after 
floods.’ — W. M. D. | 
There are young shells of at least one other Ampullaria, perhaps 
of two species, but they are too immature to be identified. 
31, Ampurtarta Datyt, sp. nov. (vel A. TurBinis, Lea, subsp. Datyz). 
Pl Nea treet 
Testa subobtecte perforata, globosa, olivacea, fasciis angustis crebris 
saturatioribus verticaliter picta, levis, striis incrementi lineisque 
