PROSOPEAS. 27 



very slender. The growth-striae are somewhat arched for- 

 ward. The description of Mousson's Bui. acutissimus applies 

 in great part, but he gives only Sy 2 whorls for a specimen 

 but little smaller, and terms the shell regularly, closely stri- 

 ate; moreover, the present shell cannot well be called "very 

 acute 77 (v. Marts.}. 



20. P. ROEPSTORFI (Morch). PI. 3, figs. 97, 98, 99. 

 "Related to Stenogyra elongatula Pfr. (Martens, Ostas. 



Zool., p. 379, pi. 22, f. 12), but differing as follows: Shell 

 straw-colored, costulate-striate, the sutures deep ; aperture 

 dilated, almost fig-shaped, white in the throat; columella 

 twisted, imperforate. Length 22.5, diam. 6, length of aper- 

 ture 7.5 mm." (Morch). 



Nicobar Is.: Kamorta (Roepstorf). 



Bulimus (Prosopeas) roepstorfi Men., Journ. de Conchyl., 

 1876, p. 358, 367. 



I figure a specimen received as P. roepstorfi. There are 

 nearly 8 whorls, the first globose and smooth, the rest moder- 

 ately convex and sculptured with forwardly arcuate, thread- 

 like striae. The aperture is quite oblique, long and narrow, 

 the thin outer lip arched forward, the columellar lip nar- 

 rowly reflexed above and imperfectly appressed. The colu- 

 mella is concave, slightly folded at the upper insertion. 

 Length 16, diam. 4.7, length of aperture 5.2 mm. 



21. P. ACHATES (Moerch). PL 12, figs. 4, 5. 



"Differs from roepstorfi by the smaller, short shell, covered- 

 perforate. Length 14, diam. 5, length of aperture about 6 

 mm." (Moerch). 



Kamorta, Nancouri, Nicobar Is. A variety from Kamorta 

 and Nancouri is "smaller, smoothish, length 11, width 9, 

 length of aperture 5 mm. ' ' Another from Nancouri is rather 

 solid, length 13, width 4.16 mm., aperture 4 mm. 



Bulimus (Prosopeas) achates MOERCH, J. de Conch., 1876, 

 p. 359. 



Morch places Stenogyra achatinacea Pfr. in the synonymy 

 of his achates, without explanation of so irregular a course. 



