OPEAS, CHINA. 163 



ably 0. clavulinum will be found to include some of the de- 

 scribed forms. 



44. 0. SCHENSIENSE Sturany. PI. 19, fig. 18. 



The turrited, yellowish-white shell with nipple-like apex 

 consists of 71/2 convex, delicately transversely striate whorls. 

 The umbilicus is crevice-like. Length 6.4, diam. 2.1, aper- 

 ture 1.8x1.2 mm. (Sturany). 



China: Southwestern Shen-si, in loess of the left bank of 

 the Tung-ho river (Obrutschew). 



Opeas schensiense STURANY, Denksch. Kais. Akad. Wis- 

 sensch., Wien., Ix, 1901, p. 37, pi. 3, f. 10. 



0. fauvelianum and 0. filare Hde. are related forms. 



45. 0. AMDOANUM Moellendorff. 



Shell minutely rimate, very slenderly turrited, thin, closely 

 striatulate, pale straw-colored. Spire much lengthened, very 

 slender, regularly tapering. Whorls 121/2, flattened, some- 

 what terraced, somewhat angulate at the margined, subcrenu- 

 late suture. Aperture narrowly oval, moderately excised; 

 peristome unexpanded, acute, the columellar margin shortly 

 reflexed, nearly closing the umbilical crevice. Length 11.5, 

 diam. 2.1 mm. (Mlldff.) 



China: province Gan-su, between Yu-linguan and Wen- 

 hsien ; Dshie-dshou. 



Opeas amdoanum MLLDFF., Annuaire du Musee Zoologique 

 de 1'Acad. Imp. Sci. de St. Petersb., vi, 1901, p. 390. 



'No similar slender and acute species is known to me, and 

 there is none closely related among Heude's species." 



46. 0. TURGIDUM (Gredler). PI. 20, figs. 29, 30, 31. 



Shell subperforate, turrited or conic-fusiform, thin, lightly 

 mgulose-striate, the striae arching forward, evanescent above, 

 glossy, waxen. Apex obtuse. Whorls 7^/2, convex, the su- 

 ture rather deep, last whorl rounded below, one-third the 

 total length. Aperture subvertical, narrowly piriform; 

 columella subarcuate, vertical, scarcely truncate; columellar 

 margin dilated and reflexed above, adnate, gradually taper- 



