172 LAND AND FEESHWATER 



p. 152, as Austenia? salia, Bs., var., a smaller or more solid 

 shell. 



Size: major diam. 11*3, alt. axis 6 mm. 



The shell is of the type of A. plunospira, but may be distinguished 

 at once by the coil of the whorls, there being more of them. The 

 shell is so thin and delicate, that I found it impossible to detach it 

 from the animals preserved in spirit. 



Animal (figs. 5, 5 a). Of similar form to A. planospira ; the 

 principal difference is noticeable in the shell-lobes, which in this 

 species are quite smooth, whereas in planospira they are strongly 

 papillate. The left shell-lobe shows a scalloped edge, with furrows 

 running inwards towards the edge of the mantle. The left dorsal 

 lobe is distinctly in two parts. The sides of the foot and mantle- 

 lobes are mottled, but not strongly, and one specimen shows this 

 only slightly on the shell-lobes. The sole of the foot is divided, 

 but the segmental lines on the side do not extend across the central 

 portion as in A, gigas and other species. The fringe of the foot is 

 paler than the rest of the animal, from the peripodial groove to the 

 edge of the foot. 



The generative organs (fig. 9) are interesting, because in the penis 

 there is a solid coiled rounded mass at the main bend, from which 

 the retractor muscle is given off, and in this respect this species 

 shows an approach to Macrochlamys ; yet again in this connection 

 there is also a well-developed kale-sac or flagellum at the point of 

 junction of the vas deferens *. The amatorial organ is short and 

 blunt at the outer end ; in this respect it is like that seen in the 

 genitalia of Austenia planospira. The spermatheca is apparently 

 long, only a part, perhaps half, is left, a portion having been broken 

 off in dissection. 



The jaw was arched, solid, and with a strong central projection. 

 The radula has the formula 



25 . 16 . 1 . 16 . 25 

 41 . 1 . 41 



The teeth are similar in form to those of A. bensoni of Calcutta, 

 the outer cusp lying low down, up to the extreme marginals. 



Austenia. durrangensis, n. sp. (Plate CVIII. figs. 5, 5 a, oh; 

 Plate CXI. figs. 7-7 c.) 



Durrang District, Assam. 



Shell depressedly globose, not umbilicated ; sculpture none, 

 surface glassy, crossed transversely by fine lines of growth ; colour 

 straw-colour : spire very low, rounded ; suture shallow ; whorls 2|, 

 expansive ; aperture very oval, oblique ; peristome thin, narrowly 

 edged with white ; columellar margin nearly vertical. 



* Compare this male organ with that of A. planospira, Bs. (Plate XXXVIII. 

 fig. 1), ill which it will be seen that the organ is of simpler form, there is no coil 

 and no kale-sac, and in this respect it assimilates to the penis of A. gifjns, the 

 tjpe of the genus. Compare also with fig. on. Plate CVII. 



