1894.] LAND-SHELLS from; the samtji islands. 151 



Fam. STENOGYBIDiE. 



14. Opeas geacile, Hutt. 



15. Opeas pilieoeme, sp. nov. (Plate XVI. fig. 11.) 



T. rimata, gracillime turnta, tenuis, svhtiliter et maxime confertiin 

 striatula, nitens, pellucida, albida ; spira sens-im attenitata, apice 

 obtusido. Anfr. 7^, convexiusculi, lente accrescentes, siUura sat 

 impressa discreti. Apertura modice obllqua, anguste acuminato- 

 ovalis ; peristoma rectum, acutum, margiae columellari incrassa- 

 tulo rejlexo. 



Alt. 5*5, diam. 1'5 millini. 



I do not know any similar small and slender species of Opeas ; 

 the comparatively great number of whorls show that it is adult. 



Fam. PupiD.!. 



16. Veetigo (Staueodon) moreleti, Brown. 



Subsp. nov. SAMTTIANA. 



Differs from the Borneo and the Philippine-Island type (v. 

 Jahresb. Senckenb. nat. Ges. 1890, p. 252) in the shghtly more 

 contracted shell and in the somewhat deeper groove behind the 

 outer peristome. 



17. HypsELOSTOMA TEANSiTANS, sp. nov. (Plate XVI. figs. 12, 

 13.) 



T. iimhilicata, turbinata, oblique striatula, fusca. Anfr.4,convexi, 

 spiram conicam apice papiiUai-i form ant es ; ultimus paullum 

 distortus, antice non ascendens, breviter solutiis et porrectus, ad 

 peripheriam crista sat prominente, altera minore ad suturam, 

 cinctus, basi subgibber, circa umbilicum compressus. Apertura 

 jiarum obliqua, rotundato-tetragona; peristoma continuum, tenue, 

 exjmnsum, haud rejlexum. Lamella parief alls validiuscula, antice 

 hijida, dentibus 2 in margine externa, 1 in basi et 1 in colu- 

 mella oppositis. 

 Biam. 2-75, alt. 2'66 millim. 



This peculiar shell presents an especial interest inasmuch as it 

 forms a decided transition from Hypselostoma to the Indian and 

 Chinese Boysidia, Ancey, of which Pupa hunanensis, Gredl., is the 

 type. As 1 have mentioned in the description of Hypselostoma 

 hungerfordianum (P. Z. S. 1891, p. 338), the genus appears to be 

 but an extreme development of the Boysidia type. Boysidia 

 strophostoma, Mdff., of South China, shows already a slight distor- 

 tion and detachment of the last whorl, which in the Samui species 

 is much less developed than in the other forms of the genus. 

 There can be no doubt, however, that it belongs to Hypselostoma, 

 with which it has the pecuUar quadrangular shape of the last 

 whorl and the dentition of the aperture in common. H. cmssei, 

 Mor., of Tongkin seems to connect it with the other Mahiyan 

 species. 



