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VIVIPABA. 87
Var. tezpurensis (Nevill), Cat. Moll., Fasc. E, p. 35.
"A very interesting form, almost exactly intermediate between
P. crassa and P. siamensis. Spire much shorter than in typical
form, and only a little more produced than in the Siam species ;
whorls more globose; aperture less deflected, umbilicus less open,
sculpture more distinctly malleated "
Alt. 17'5, diam. lo"5 mm.
Aperture: alt. 9'5, diam. 11-5 mm.
Hab. Tezpur. •
173. Vivipara siamensis (Frav.enfeld).
Vivipara siamensis (Frauenfeld), Verli. zool.-bot. Ges. Wien, 1865,
p. 531, pi. 22,; Nevill, S. A. S. B. xlvi, pt. 2, p. 32, & op. cit. 1,
p. 32.
Shell solid, aeuminately conic, flattened below, widely perforate,
somewhat polished, very pale olive-green, margins of the
upper whorls almost whitish, the third and fourth convolutions
tinged with purplish-brown ; whorls 5, very convex, though
somewhat flattened in the sutural region, marked wirh faint
growth lines which show darkly here and there and sculptured
with weak, interrupted, spiral striae ; aperture large, broad ;
labrum thick, black ; interior of shell white ; operculum thin,
pale brownish, with very excentric nucleus.
Alt. 24, diam. 21 mm.
Aperture : alt. (including the labrum) 17'5, diam. 14-5 mm.
llah. Siam.
Var. burmauica {Nevill), Hand List, pt. 2, p. 26.
Original description :—A very small variety; spire short, apex
obtuse, with the whorls even less acute and exserted, the last one
larger in proportion and more globosely swollen, with the keel
round the umbilicus obsolete ; aperture more contracted, that is,
less dilately expanded; colouration of epidermis and the black
peristome exactly similar.
Alt. 11, diam. 10 mm.
Hah. Prome, on the Irawady (type) {Theobald); Tenasserim
Province {Limborcj); Taylaymavv, tipper Burma {Anderson).
174. Vivipara dissimilis {Mutter).
Vivipara dissimilis (Midler), Verm. pt. 2, p. 184 (as Nerifa.);
. Schroter, Einleit. Conch, ii, p. 253, pi. 4, iig. 10 (Nerita).
Helix dissimilis, Gmelin, Sysl.. Nat. 3647 ; Dillwyn, Desc. Cat.
p. 941 {Nerita).
Paludina refuossit, Kiister (not Philippi), ed. Chemn., Pahcdina,
p. 26, pi. 5, figs. 17, 18; 11. & T., C. 1. pi. 77, figs. 3, 4.
Original description :—Testa pellucida glabra f uscescente-alba ;
albido maxime in inferiore anfractus parte conspicitur, quasi