300 ZCXNITID^E. 



marginals, each with two subequal points. The central tooth 

 is either tricuspid with large lateral cusps close to the apex, or 

 devoid of lateral cusps. Lateral teeth bicuspid. In a specimen of 

 I), retrorsa there were on each side 12 inner lateral teeth and 45 

 marginals. The jaw had no inner median projection. 



[The generative organs, as shown in the type, are peculiar, the 

 amatorial organ having a bunch of secretory glands at the free end 

 and a long slender calcareous dart.] 



470. Dyakia? retrorsa, Gould (Helix), Host. Jour. N. H. iv, 1844, 

 p. 455, pi. 24, fig. 4 ; Pfr. (Helix) Mon. Hel i, 1848, p. 76 ; id. 

 t. c. vii, 1876, p. 128 ; H. 8> T. (Helix) C. I. 1876, pi. 25, fig. 6; 

 Godivin-Austen (Ariophanta), Mol. 2nd. i, 1883, pp. 133, 136, 

 pi. 34, figs. 4-8 ; id. (Semperia) t. c. ii, 1898, p. 82 ; v. Mart. 

 Nanina (Hemiplecta), Jour. Linn. Soc. xxi, 1889, p. 161. 

 Helix saccata, Pfr. P. Z. S. 1854, p. 49 ; id. Mon. Hel. iv, 1859, 

 p. 30 5 id. t. e. vii, 1876, p. 96; Godwin-Austen, J. A. S. . 

 1880, 2, p. 153. 



Shell sinistral, narrowly umbilicated, thin, obliquely striated 

 and marked, on the last whorl especially, above and below, with 

 fine spiral, slightly undulating wrinkles ; spire conoidal, with an 

 acute apex, suture emarginate ; whorls 2J, rapidly increasing, 

 flatly convex above, the last cornpressedly keeled at the periphery, 

 swollen beneath, not descending ; aperture diagonal, ovally lunate ; 

 peris tome thin. 



Major diam. 45, min. 36, height 23 mm, 



Hob. Tenasserim ; Tavoy and Mergui ; Mergui Archipelago. 



[The generative organs of D. ? retrorsa have not yet been 

 examined, and it is to be seen whether they conform to the sinistral 

 type species (D. hugonis of Borneo) or not.] 



[Dr. Blanford's manuscript included the genera Parmacella and 

 Vitrina, both of which I consider will be better brought into the 

 volume on the Helicida3, and after Trochomorpha, which I trust 

 may follow next in the 'Fauna of British India' (Mollusca). In 

 the genus Vitrina are included three species : pellucida, a typical 

 species, and two others which cannot be said to be so, viz. 

 papittaspira, Godwin- Austen, from the Khasi Hills, and canefrii= 

 birmanica, Tapparone Canefri; it was this naturalist who con- 

 sidered a species obtained by M. Fea at Bhamo to be the same as 

 Austenia papillaspira. I would call attention to the fact that 

 the Bhamo shell was never compared with the type in my col- 

 lection, and that it is by no means certain the animals are alike, 

 that of the Khasi form being unknown, while the Bhamo species 

 is described as having no mucous pore, and for this reason alone 



