MOLLUSCA OF INDIA. 293 



descending in front, rounded at the peripliery, convex beneath ; 

 aperture oblique, diagonal, ovately lunate ; peristome thin, upper 

 margin slightly depressed, columellar oblique, reflected." 



The specimen figured is one from Bassein in Blanford's Col- 

 lection, now in the B.M. Collection. The type from Pingoung 

 was presented to same Museum by Mr. John Ponsonby. 



I said in 1 888, it is not like levicula, which has a very thin and 

 glassy shell, is much more globose, and with a higher spire. I 

 put it only provisionally in Durgella. The distinct umbilication 

 is unlike any shell of this type I have seen. 



Size of shell figured : maj. diam. 8'8, min. 7'4 ; alt. axis 4 mm. 



Genus Leptodontabion. 

 {Continued from Vol. II. p. 208.) 



Leptodontaeion tavotensis, n. sp. (Plate CXXVII. figs. 

 3-3 e.) 



Locality. Tavoy, Tenasserim {Captain SfanJerj Floiuer). 



Animal (figs. 3, 3 a). Poot throughout grey-green, the shell-lobes 

 black. Foot with a long overhanging lobe ; peripodial margin 

 well defined, th^ee grooves above it ; the head is depicted contracted 

 under the edge of the left dorsal lobe. ISole of foot (fig. 3 b) has 

 a narrow central area, well defined from the two narrow areas 

 on either side ; the mucous pore is underneath the overhanging 

 portion and reaches to the tip of it. The left shell-lobe broad and 

 pointed behind, the right also broad and square behind. 



Length of animal 15'5; shell, maj. diam. 7'5 mm. 



Jaw (tig. 'dd) slightly arched, no central projection, thin and 

 delicate. 



The radula (fig. 3t;) is very broad, apparently nearly as broad 

 as long, with a very great number of very close-set teeth, all of 

 the same shape, becoming gradually smaller on the outer margin ; 

 unfortunately the radula is folded up, and when once this occurs 

 it is almost impossible to flatten it out without still further 

 destruction, the whole is so small and so fragile, thus I could not 

 find the central tooth. The teeth are on elongate narrow plates, 

 bicuspid, one cusp slightly longer than the other ; very similar to 

 those of L. minuta, G.-A., of the Dafla Hills. There are probably 

 more than 600 teeth in the row. 



Genitalia (fig. 3 c) : only the male organ and amatorial organ 

 secured, the former is of simple form, bent on itself at the 

 retractor muscle, the latter is short, thick and pointed. 



The shell is very thin and membranaceous, of a burnt-sienna 

 colour, globose in form ; surface smooth. Whorls 3, increasing 

 regularly, the last tumid. 



