212 GYLIAUCHEN. 



Ava : Mya Leit Doung. 



Hypselostoma bensonianum BLANFORD, Jourii. As. Soc, 

 Beng., vol. 32, 1863, p. 326. PPR., Monogr., v, 437. HANLEY 

 & THEOBALD, Conch. Indica, 1870, pi. 8, f. 2. GUDE, Fauna 

 Brit. India Mollusca, ii, p. 299. 



The differences between this shell and Hypselostoma tiibi- 

 ferum Benson, hitherto the only known species of the genus, 

 are numerous. That shell has the spire scarcely exserted, 

 while the last whorl ascends so much that the mouth, which is 

 horizontal is on a level with the apex. In the present species 

 the spire is conical, the mouth nearly vertical, and the last 

 whorl only ascends very slightly (Blanford). 



1 ' Some specimens in the Theobald collection measure : 

 major diam. 3, min. 2, alt. 2 mm. (including the peristoine) ' 

 (Gude). 



The angular and parietal lamellae are parallel, not converg- 

 ing, both being rather short and slender. Infraparietal is 

 minute, rather deeply placed. Columellar lamella rather 

 small. Upper and lower palatal plicas are well developed, the 

 lower somewhat larger. Basal fold small. The last whorl 

 runs up more, and the free part is not so long as in G. hunger- 

 fordianus. Fig. 12 is from Conchologia Indica, fig. 11 from 

 a specimen in mus. A. N. S. 



2. GYLIAUCHEN HUNGERPORDIANUS (Moellendorff). PI. 36, 

 figs. 1-4. 



Shell rather openly umbilicate, turbiuate, thin, corneous- 

 brown, opaque. Whorls 4^, angulate-convex, separated by a 

 much impressed suture, slightly striatulate, the upper form- 

 ing a concave, turrited-conic spire with mamillar, slightly 

 excentric apex. Last whorl having a projecting, rounded keel 

 at the periphery, another more obtuse one at the umbilicus, 

 encircled by lightly impressed spiral sulci above and below 

 the peripheral keel; its last fourth free, running forward, 

 slightly ascending, almost tetragonal in the free part, at the 

 base spirally lineolate. Aperture nearly vertical, very slightly 

 looking upward, rounded-quadrangular, contracted by seven 

 lamelliform teeth within, of which four larger form a cross; 



