Rissoa.] GASTROPODA. 207 



Diameter, 1 mm. ; height, 2 mm. 



Animal unknown. 



Type in my collection. 



Hab.--Tv Onepoto, near Lyttelton, type (H. S.) ; Lyall Bay 

 and Titahi Bay (Miss Mestayer) ; near the Bounty Islands, in 50 

 fathoms, and Taumaki Island, South Island, in 10 fathoms (Captain 

 Bollons). 



Remark. The blackish-brown colour of the type specimen was 

 no doubt produced by black mud, in which the specimen had very 

 likely been lying for some time. All specimens I have seen later on 

 were translucent white. 



13. Rissoa insculpta, Murdoch, 1905. Plate 12, fig. 13. 



Bissoa insculpta, Murdoch, T.N.Z.I., xxxvii, 1904 (1905), 229, pi. 8, f. 28. 



Shell small, elongate, slightly rimate, rather fragile. Sculpture 

 consisting of minute spiral threadlets, about 16 on the penultimate 

 whorl, and on the last about 25, of which 17-18 are in front of the 

 aperture ; these are crossed by irregular growth-lines, here and there 

 rather pronounced. Colour white. Spire elevated conical, higher than 

 the aperture ; outlines slightly convex. Protoconch small, globose, of 

 1^ smooth whorls. Whorls 5, lightly rounded ; base convex. Suture 

 impressed. Aperture broadly ovate, slightly oblique, angled above. 

 Peristome continuous. Outer lip slightly thickened, and projecting 

 from the whorl above. Operculum unknown. 



Diameter, 1-35 mm. ; height, 2-56 mm. 



Animal unknown. 



Type in the Dominion Museum, Wellington. 



Hob. Whangaroa Harbour, type (C. Traill) ; Port Pegasus, 

 Stewart Island, in 18 fathoms (Captain Bollons) ; 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 (Iredale). 



Remarks. This form is near to R. foveauxiana, Sut. It differs 

 in being more slender, more feebly rimate, sculpture much finer, suture 

 less deep, and the whorls less rounded. 



Subgen. 5. CINGULA, Fleming, 1828. 



Cingula, Fleming, Brit. Anim., 1828, 297, 305. Type : R. cingillus, Montagu. 

 Sabincea, Leach. 



Shell thin, smooth or microscopically spirally striated ; whorls 

 flat, occasionally spotted or banded near the suture ; outer lip sharp, 

 or slightly thickened. 



