Odostomia.] GASTROPODA. 339 



of 1 whorl, smooth. Whorls 6, regularly increasing, the last rather 

 high, but slightly convex, body-whorl sometimes faintly angled at the 

 periphery ; base flat. Suture impressed, narrowly and rather in- 

 distinctly margined below. Aperture subvertical, narrowly pyriform, 

 rounded and produced below. Outer lip slightly convex, sharp. 

 Columella somewhat oblique, arcuate, with a distinct oblique and 

 deeply placed plait above. Inner lip narrow above, but broadening 

 towards the base, spread as a thin callus over the parietal wall. Some- 

 times there is a very narrow umbilical chink present. Operculum 

 unknown. 



Diameter, 2-5 mm. ; height, 6-1 mm. 



Animal unknown. 



Type in my collection. 



Hob. Near the Snares (type) and Bounty Islands, in 50 fathoms 

 (Captain Bollons). 



Remark. This species is apparently nearly allied to 0. hi/phala, 

 but the whorls are not slightly scalar, the suture is less deep, the 

 columellar plait stronger, &c. 



10. Odostomia stygia, n. nov. Plate 16, fig. 23. 



Odostomia maryinata, M. & S., T.N.Z.I., xxxviii, 1905 (1906), 296, pi. 25, 

 f. 37 ; not of C. B. Adams, 1852. 



Shell small, ovate, white and shining, almost smooth, with a mar- 

 gined suture and angled body-whorl. Sculpture consists of distinct 

 flexuous growth-lines, irregularly spaced, and with much finer incre- 

 mental strise between them ; with a magnifying - power of about 

 30 diameters distant fine spiral striation can be made out. Colour 

 white ; fresh specimens semitransparent, but dead shells porcellanous. 

 Spire elevated, conical, 1J times the height of the aperture ; outlines 

 very slightly convex. Protoconch heterostrophe, of 2 smooth tilted 

 whorls, nucleus lateral. Whorls 6, flatly convex, the last angled at 

 the periphery, rather rapidly but regularly increasing ; base convex. 

 Suture impressed, distinctly margined below. Aperture pyriform, 

 angled above, rounded and slightly effuse below. Peritreme discon- 

 tinuous. Outer lip sharp, flatly convex, acutely rounded at the base. 

 Columella with a very distinct plait just below the junction with the 

 parietal wall, concave belcw. Umbilicus represented by a distinct 

 chink. Operculum unknown. 



Diameter, 2-3 mm. ; height, 4-5 mm. 



Animal unknown. 



Type in the Dominion Museum, Wellington. 



Hob. Off Great Barrier Island, in 110 fathoms (type) ; dredged 

 off Otago Heads (A. Hamilton) ; near Channel Island, Hauraki Gulf, 

 in 25 fathoms ; Port Pegasus, Stewart Island, in 18 fathoms (Captain 

 Bollons) ; Banks Peninsula (Iredale). 



