28 PROSOPEAS. 



I have figured a Nicobar shell which seems to me referable to 

 Mo rch's form. It is rather obese below, subregularly taper- 

 ing to the obtuse, smooth apex, sculptured with narrow, 

 spaced, thread-like riblets which curve forwards above the 

 periphery and are much weaker below it. Whorls slightly 

 more than 7, moderately convex. The aperture is long, the 

 outer lip arched forward above, and the columella reflexed 

 narrowly, leaving a narrow umbilical fissure. Length 13.3, 

 diam. 4.5, length of aperture 5.5 mm. 



This form seems to differ from P. achatinaceum by its 

 larger aperture. 



22. P. HAUGHTONI (Benson) . PI. 6, figs. 76, 78, 79. 



Shell imperforate, oblong-conic, subturrited, solid, striate, 

 costulate-striate towards the apex and suture. Whitish, cov- 

 ered with a very finely corrugated olivaceous cuticle. Spire 

 long-conic, suddenly tapering towards the somewhat obtuse 

 apex ; suture impressed. Whorls 7, a trifle convex, rather 

 flattened, the last whorl subangulate towards the periphery. 

 Aperture slightly oblique, ovate-elliptical, blue-whitish inside, 

 the right margin thin, acute, columellar margin callous, flat, 

 a little expanded, slightly emarginate towards the base, the 

 margins joined by a thin, expanded, parietal callus. Length 

 20-30, diam. 10-11, aperture 11 mm. long, 5 wide (Bens.). 



Andaman Is.: Port Blair (Dr. Walker; Maj. Haughton). 



Spiraxis haughtoni BENS., Ann. Mag. Nat. Hist. (3d ser.), 

 xi, p. 90, with var. oxynter Bens. (Feb., 1863). PPR., 

 Monogr., vi, p. 189. HANLEY & THEOB., Conch. Ind., pi. 19, 

 f. 1; pi. 79, f. 5 (var.). 



Two typical examples of this species before me measure: 

 length 27, diam. 10.7, length of aperture 10.5 mm., and 28, 

 11, 10.7 mm., both having a trifle over 7 whorls. They are 

 solid, strong shells, nearly denuded of the thin, olivaceous- 

 yellow cuticle. The columella is distinctly sigmoid, and the 

 parietal callus arising from it is wholly appressed at the edge, 

 not raised seam-like as in P. pcalei. 



22a. Var. oxynter Benson. PI. 6, figs. 77, 82, 83, 84. 



"Shell long-turrited, more slender. Length 30, diam. 8 mm. 



