180 HYPSELOSTOMA. 



as viewed from above, at the periphery carinate, ascending- 

 towards the aperture, inflated next to the suture above, then 

 subconvexly sloping, below impressed at the carina; convex, 

 and radially rib-striate around the umbilicus. Aperture en- 

 tire, turned upward, irregularly oblong, toothed one strong, 

 entering parietal lamina, another smaller columellar, sur- 

 rounding a little channel. Peristome thickened, continuous, 

 free, the outer margin spreading. Diam. maj. 5, min. 4, alt. 

 2mm. (MabiUe). 



Tonkin. 



Tonkinia mirabilis MABILLE ("Moll. Tonk. Diag., p. 9; 

 May 14, 1887") ; Bull. Soc. Malac. de France, iv, 1887, p. 123, 

 pi. 1, f. 4, 5. 



The figures, which I copy, are incorrect, according to Ma- 

 bille. "The apertural lamellae and the gutter have not been 

 represented; the aperture is not elevated enough, and the 

 carina is not shown." The gutter mentioned is, I suppose, 

 the sinulus, commonly more or less conspicuous in Hypse- 

 lostoma. 



3. HYPSELOSTOMA ANNAMITICUM Moellendorff. 



Shell perforate, irregularly trochiform, rather thin, deli- 

 cately striatulate, decussated by microscopic spiral lines, 

 rufous-brown. Spire elevated conic, the apex somewhat ob- 

 tuse, glossy. Whorls 5%, subangularly convex, separated by 

 a deeply impressed suture, the last whorl ascending in front,, 

 shortly free and built forward, indistinctly angular in front 

 of the suture, below the periphery and in the middle of the 

 base. Aperture nearly vertical, rounded-trapezoidal; peri- 

 stome continuous, moderately expanded, spreading. Parietal 

 lamella bifid, strong, deeply entering; columellar lamella 

 strongly elevated, deep ; 3 palatal teeth, two larger plicae 

 forming a cross with their opposites, the third basal, small. 

 Diam. 3.5, alt. 3.8 mm. (Mlldff.). 



Annam: Phuc-son (Fruhstorfer). 



Hypselostoma annamiticum v. MLLDFF., Nachrbl. Deutschen 

 Malac. Ges., vol. 32, Oct. 1900, p. 133. 



H . transitans of Samui is understood to be the nearest rela- 



