206 GASTROPODA. [Pectinibranchia. 



KEY TO SPECIES. 



A. Shell subcylindrical ; about 10 spirals on the penultimate 



whorl, insterstices of the same width as the riblets . . fumata. 



B. Shell elongately oval. 



a. About 9 spii-als on the penultimate whorl, interstices half 



the width of the riblets ; suture deep . . . . foveauxiana. 



aa. About 16 spirals on the penultimate whorl ; suture im- 

 pressed . . . . . . insculjiln. 



11. Rissoa foveauxiana, Suter, 1898. Plate 12, fig. 11. 



Rissoa foveauxiana, Suter, P. Mai. S., iii, 5, f. 2 in text; Murdoch, 

 T.N.Z.I., xxxvii, pi. 8, f. 27. 



Shell minute, ovate, rimate, translucent white. Sculpture consist- 

 ing of close, rather broad and flat spiral striae, about 9 on the pen- 

 ultimate whorl, crossed by fine growth-lines, interstices about half the 

 width of the lirae. Colour white. Spire high conical, higher than the 

 aperture, outlines convex. Protoconch small, papillate, of 1J smooth 

 whorls. Whorls 5, convex ; base rounded. Suture deep, but not chan- 

 nelled. Aperture subvertical, ovate. Peristome continuous, sharp, 

 very little thickened. Basal lip but slightly expanded. Columetta 

 oblique, arcuate, moderately callous. Umbilical tract with a narrow 

 chink. Operculum unknown. 



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



Animal unknown. 



Type in my collection. 



Hob. Foveaux Strait, in 10-15 fathoms (type) ; Lyall Bay (Miss 

 Mestayer) ; Whangaroa Harbour (C. Traill) ; near the Snares and 

 Bounty Islands, in 50 fathoms, and Taumaki Island, South Island, 

 in 10 fathoms (Captain Bollons) ; Dusky Sound, in 30 fathoms (R. 

 Henry) ; Banks Peninsula (Ire-dale). 



12. Rissoa fumata, Suter, 1898. Plate 12, fig. 12. 



Rissoa fumata, Suter, P. Mai. S., iii, 5, f. 1 in text ; Murdoch, T.N.Z.I., 

 xxxvii, pi. 8, f. 26. 



Shell minute, subcylindrical, thin, imperforate, translucent. Sculp- 

 ture consisting of numerous fine and close spiral striae, about 10 on 

 the penultimate whorl, interstices nearly the same width as the lirae. 

 Colour white. Spire high, narrow, about twice the height of the aper- 

 ture ; outlines slightly convex. Protoconch papillate, of 1 J smooth 

 and convex whorls. Whorls 5, rather rapidly increasing, moderately 

 convex ; base convex. Suture impressed. Aperture slightly oblique, 

 ovate, angled above. Peristome continuous, sharp, slightly thickened. 

 Basal lip slightly effuse. Columella short, subvertical, but slightly 

 callous. Operculum unknown. 



