suter: on molltjsca fkom new Zealand. 33 



angled above. Peristome continuous, not thickened, basal lip slightly 

 expanded. Columella oblique, a little arcuate, subtruncate, inner 

 lip but little reflexed. Diam. 1-7, height 2*8 mm. 



Sab. — Hohoura Bay, North Island (Eoger Buddie). Type in my 

 collection. 



32. RiSSOINA OLIVACEA, HuttoU, U.var. LUTEA. 



Distinguished from the typical form of the species by its light 

 horn-colour, and in being a little more slender. Diam. 1-4 to 1'5, 

 height 2-5 to 2*7 mm. 



Hal. — Maloney's Eeef, Hauraki Gulf (H. S.) ; Titahi Bay, Cook 

 Strait (Miss M. Mestayer) ; Lyttelton Harbour (H. S.). Type in my 

 collection. 



33. RissoiNA EUPOLACTEA, n.sp. PL III, Fig. 35. 



Shell small, elongate, imperforate, solid, opaque, costate, not shining. 

 Sculpture: the first two whorls are smooth, the succeeding ones 

 axially costate, the riblets thick and rounded, interstices of the same 

 width as the costae, about fifteen on the last whorl, and obsolete below 

 the periphery, leaving the base quite smooth ; there is no trace of 

 spiral sculpture. Colour : the first three whorls are rufous, with 

 a narrow darker band below the suture, the rest yellowish-white ; 

 sometimes the whole shell is rufous, or with a milk-white peripheral 

 band, the base white. Spire elevated, a little more than twice the 

 height of the aperture ; outlines straight. Protoconch small, dome- 

 shaped. Whorls 5, flatly convex, the last volution high ; base convex. 

 Suture not deep. Aperture oblique, oval, angled above. Peristome 

 continuous, slightly thickened, the edge rather blunt, thin on the 

 parietal wall ; basal lip slightly expanded. Columella oblique, almost 

 straight, verv thin, Diam. 1-5, height 3*3 mm. 



^«^.— Hauraki Gulf (H. S.). 



A species allied to R. rugulosa, Hutt., but much smaller and lacking 

 spiral sculpture. Type in my collection. 



34. Omalogtra pusca, n.sp. PL III, Fig. 36. 



Shell minute, planorbiform, thin and fragile, slightly shining. 

 Sculpture consisting of very fine microscopic spiral striae, faintly 

 reticulated by growth-lines. Colour fuscous, with a few white radiate 

 streaks and irregularly scattered spots. Spire depressed. Protoconch 

 of one whorl, distinctly marked off from the next volution, spirally 

 striate. Whorls 2f , rather rapidly increasing, convex ; base concave. 

 Suture deep. Aperture circular ; peristome shai'p, straight, slightly 

 discontinuous through the intervening parietal wall. Diam. 1, height 

 •3 mm. 



Hah. — Lyttelton Harbour, on seaweeds (H. S.). Type in my 

 collection. 



35. Omalogyra bicarinata, n.sp. PL III, Figs. 37-37«. 



Shell minute, discoidal, thin, not shining. The sculpture consists 

 of two spiral keels, one above and one below the periphery. Colour 



VOL. VIII. — MARCH, 1908. 3 



