214 GASTROPODA. [Pectinibranchia. 



24. Rissoa micans, Webster, 1905. Plate 12, fig. 24. 



Rissoa micans, Webster, T.N.Z.I., xxxvii, 1904 (1905), 277, pi. 9, f. 4. 



Shell minute, oval, subrimate, smooth, polished. Colour light 

 reddish-brown. Spire conical, higher than the aperture, outlines 

 slightly convex. Protoconch minute, of 1J convex and shining whorls. 

 Whorls 4, convex ; base rounded. Suture impressed. Aperture cir- 

 cular. Peristome discontinuous, but the margins united by a parietal 

 callosity, sharp, not thickened, whitish and semitransparent. Columella 

 arcuate, very slightly reflexed. Operculum unknown. 



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



Animal unknown. 



Type in Mr. W. H. Webster's collection. 



Hob. Takapuna, type (W. H. Webster) ; Maloney's Reef, Hauraki 

 Gulf (H. S.). Hohoura Bay (R. Buddie) ; near Little Barrier Island, 

 in 20 fathoms (R. H. Shakespear) ; Titahi Bay, Cook Strait (Miss 

 Mestayer) ; near the Snares, in 50 fathoms (Captain Bollons). 



25. Rissoa microstriata, Murdoch, 1905. Plate 12, fig. 25. 



Rissoa microstriata,, Murdoch, T.N.Z.I., xxxvii, 1904 (1905), 229, pi. 8, f. 25. 



Shell minute, ovate-elongate, smooth, and white. Sculpture con- 

 sisting of microscopic dense spiral striae, broken up into variable lengths 

 by the irregular lines of growth. Colour white. Spire elevated conic, 

 higher than the aperture, outlines somewhat convex. Protoconch 

 minute. Whorls 5, somewhat swollen at the periphery, thence gently 

 flattened to the suture above. Suture impressed and lightly margined. 

 Aperture obliquely broadly ovate. Peristome discontinuous, but the 

 margins united by a parietal callus, slightly thickened, and the basal 

 lip somewhat reflected. Columella short, a little arcuate, callous, and 

 reflexed. Operculum unknown. 



Diameter, 1-08 mm. ; height, 2-11 mm. 



Animal unknown. 



Type in the Dominion Museum, Wellington. 



Hob. Whangaroa Harbour, type (C. Traill) ; near the Snares 

 and Bounty Islands, in 50 fathoms (Captain Bollons) ; Foveaux 

 Strait ; Banks Peninsula (Iredale). 



Remarks. This little shell is perhaps near to Rissoina neozelanica, 

 Suter, while the sculpture, though microscopic, may be compared with 

 Rissoa emarginata, Hutton, a Pliocene form. (Murdoch.) 



26. Rissoa neozelanica, Suter, 1898. Plate 13, fig. 1. 



Barleeia neozelanica, Sut., P. Mai. S., iii, 8, f. 5 in text. 



Shell minute, ovate-conical, imperforate, subpellucid, white, thin, 

 smooth, and shining. Sculpture consisting of fine oblique growth-lines, 

 and a few (usually 3) spiral striae around the umbilical area. Colour 

 white. Spire conical, a little higher than the aperture ; outlines 



