o TESTACELLIDJE. 



B. Penultimate whorl sharply keeled ; shell much depressed. 

 a. Base of last whorl smooth and polished. 



9. Streptaxis exacutus, Gould, Proc. Bost. Soc. N. H. vi, 1856, p. 13 ; 



Pfr. Mon. Hel iv, 1859, p. 331 ; id. t. c. vii, 1876, p. 494 ; H. $ T. 

 C. I. 1876, pi. 98, figs. 8, 9, 10 ; Nev. Hand-l. i, 1878, p. 3. 



Shell openly umbilicated, whitish, finely and flexuously costulate 

 above, less closely on the last whorl, which is smooth beneath, 

 except behind the peristome ; spire very low ; whorls 6|, flat above, 

 the penultimate with a compressed keel which projects consider- 

 ably beyond the last whorl, the latter convex around the umbilicus ; 

 breadth of body-whorl, seen from beneath, less than that of 

 penultimate ; aperture truncately oval, two parietal lamellae, one 

 in the middle of the parietal wall, the other smaller, close to the 

 outer angle; peristome white, expanded, very slightly arcuate 

 above on the outer border. 



Length 12|, breadth 7|, height 6 mm. 



Hal). Moulmein (Stoliczka) ; Mergui (Mus. Cum.). 



b. Shell finely costulate throughout, above and below. 



10. Streptaxis sankeyi, Bs. A. M. N. H. (3) iii, 1859, p. 472; Pfr. 



Mon. Hel. v, 1868, p. 442 ; id. t. c. vii, 1876, p. 494. 

 Streptaxis sankeyanus, Stol. J. A. S. B. xl, pt. 2, 1871, p. 167, pi. 7, 

 fig. 14 ; Nev. Hand-l. i, 1878, p. 3. 



Shell very like that of S. exacutus, but the keel on the penulti- 

 mate, though sharp, is not compressed, whilst the body-whorl is 

 angulately compressed around the umbilicus. Only a single 

 parietal lamella ; columellar border of peristome quite straight. 



Fig. 7. Streptaxis sanJceyi. 



Length 11 J, breadth 7-j, height 5| mm. ; a smaller specimen 

 measures 10, 6|, and 5 mm. 



Hob. Farm Caves, near Moulmein (Stoliczka) ; Mergui (Mus. 

 Cum.). 



11. Streptaxis hanleyanus, Stol. J. A. 8. B. xl, pt. 2, 1871, p. 168 



pi. 7, fig. 15 ; Pfr. Mon. Hel. vii, 1876, p. 494. 

 Streptaxis sankeyi, H. $ T. (nee Benson) C. I. 1876, pi. 8, fig. 7 ; 

 Nev. Hand-l. i, 1878, p. 3. 



