Leuconia.] GASTROPODA. 593 



convex, its height less than that of the aperture. Protoconch small, 

 obtuse. Whorls 6, gradually increasing, last large, compressed below 

 the suture, flattened at the periphery and rounded at the base. Suture 

 channelled. Aperture auriculate, slightly oblique. Outer lip sinuous, 

 neither thickened nor reflected. A small but sharp and deeply seated 

 plication occurs on the body-whorl, anterior to the centre ; immedi- 

 ately in front of this, and deeper still, is a second ill-developed fold. 

 A heavy callus is spread on the body-whorl. 



Diameter, 1-16 mm. ; height, 3 mm. (type). 



Animal unknown. 



Type in the Australian Museum, Sydney. 



Hob. Takapuna (W. H: Webster). The type is from Sydney 

 Harbour. 



Remarks. Iredale is of opinion that only one species, L. obsoleta, 

 should be recognised as occurring in New Zealand, and he feels certain 

 that the examination of a larger series from Takapuna will induce 

 Webster to withdraw his record of L. inermis, Hedley. 



2. Leuconia obsoleta, Hutton, 1878. Plate 24, fig. 4. 



Leuconia obsoleta, Hutt., J. de Conch., xxvi, 1878, 43 ; T.N.Z.I., x, 1877 

 (1878), 297; M.N.Z.M., 34; Hedley, P.L.S. N.S.W.. xxv, 723, pi. 48, 

 f. 16 ; Iredale, T.N.Z.I., xl, 385. 



Shell small, ovate, thin, semitransparent. Sculpture consisting of 

 fine spiral strife, close together on the base, But more distant on 

 the upper part of the body-whorl, crossed by fine oblique growth- 

 lines. Colour whitish. Epidermis very thin, light brown. Spire short, 

 conic, about three-quarters the height of the aperture ; outlines 

 convex. Protoconch small, papillate. Whorls 4, lightly convex, the 

 last ventricose, large, compressed below the suture ; base rounded. 

 Suture not much impressed. Aperture ovate, angled above, roiinded 

 below. Outer lip slightly sinuate above, straightened at the middle, 

 thin and sharp, smooth inside. Columella subvertical, flat, concave 

 below, with a distinct sharp transverse plait at the junction with the 

 flattish parietal wall, and a small low tubercle below. Inner lip thin, 

 inconspicuous. 



Diameter, 1-7 mm. ; height, 3-1 mm. 



Dentition. Riitton, T. N.Z.I., xvi, 213. 



Type in the Otago University Museum, Dunedin. 



Hob. Auckland Harbour, under stones near high-water mark, 

 local ; type (Cheeseman) : Titahi Bay, Cook Strait (Miss Mestayer) : 

 Taumaki Island, in 10 fathoms (Captain Bollons) : Lyttelton Harbour 

 (Iredale) : Shag Point, Otago (Iredale). 



Remarks. The shell is very variable in size and shape, some shells 

 being almost globular, with the spire-whorls very compressed ; others 

 are elongated and narrow, with the spire-whorls lengthened. The 

 spiral striation may be very distinct, indistinct, or almost indistin- 



