1076 MALAYSIAN LAND AND FRESHWATER MOLLUSCA, 



Fig. 4. Radula of do. — A, central tooth ; B, lateral tooth ; CV 

 first marginal tooth ; D, second marginal tooth. 



Fig. 5a. Portion of one of the mandibular plates (veiy much 

 enlarged). 



Fig. 5b. Details of do., on a much larger scale. 



Figures 1, 2, 3 are magnified two diameters. 



Hybocystis elephas, De Morgan, Le Nat. VII. 1885, No. 9, 

 p. 70 ; von Mi5ll. Jour. As. Soc. Beng. LV. 1886, p. 314. 

 Perak. 



H, joussEAUMEi, De Morgan, I.e. p. 70 ; von Moll. I.e. p. 315. 

 Valley of the Plus river. 



Family HYDROCENID^E. 



33. Georissa, Blanford, 1864. 



Ann. and Mag. Nat. Hist. 3rd series, XIII. 1864, p. 463 ; ibid. 

 4th series, III. 1869, p. 173. 



Type Hydroeena pyxis, Benson. 



Shell resembling that of Hydrocena, imperforated, small, conical, 

 amber or reddish-coloured, spirally sulcated or striated. 



Animal furnished with hemispherical lobes in the place of tenta- 

 cles ; eyes normal ; foot short, rotund. Operculum semi-oval, no 

 spiral structure as in Helicina ; excentrically striated, testaceous, 

 transparent. 



Georissa monterosatiana, Godwin-Austen and G. Nevill, 

 Proc. Zool. Soc. 1879, p. 739, pi. 59, fig. 6 ; von Moll. Jour. As. 

 Soc. Beng. LV. 1886, p. 316. 



Bukit Pondok. 



G. SEMiscuLPTA, Godwin- Austen and G. Nevill, I.e. p. 740, 

 pi. 59, fig. 3, 3a ; von Moll. I.e. p. 316. 

 Bukit Pondok. 



