666 GASTROPODA. [Pulmonatfi.. 



over the whole shell, most developed on the upper surface, usually a 

 few larger spots near the suture. Epidermis thin, dull. Spire de- 

 pressed conoidal, outlines slightly convex, its height about half that 

 of the aperture. Protoconch flatly convex, smooth, sometimes indis- 

 tinctly radially costate, of If whorls. Whorls 5, convex, gradually 

 increasing, body-whorl rounded, higher than broad (slightly angulated 

 in the young), not descending. Suture impressed. Aperture oblique, 

 rotundly lunate. Peristome simple, straight, margins slightly ap- 

 proaching. Columella oblique, arcuate. Inner lip slightly thickened, 

 and rather broadly dilated above, white. Umbilicus deep, about 1 mm. 

 in diameter, usually whitish within. 



Diameter Maj., 8-8 mm. ; min.. 5-5 mm. : height, 4-5 mm. 



Dentition typical. 



Type unfortunately destroyed by fire, but co-types are in my 

 collection. 



II ab. Wanganui ; Cape Egmont (R. Murdoch). 



Remarks. This species resembles very much the local variety 

 of Phacussa hypopolia, Pfr., from Pelorus Valley, and no well-marked 

 characters separate the shells of the two. but the dentition of the two 

 species is quite distinct. 



4. Phenacohelix pilula, Reeve, 1852. Plate 26, fig. 7, a, b. 



Helix pilula, Reeve, Conch. Icon., vii. gp. 809. Phenacohelix pilula, Reeve : 

 Hedley and Suter, P.L.S. N.S.W. (2), vii, 641. Flammulina (Phenaco- 

 helix) pilula, Reeve : Suter, J. de Conch., xli, 249 ; P. Mai. S., ii, 284, 

 figs, in text. Helix iota, Pfeiffer, M.H. Viv., iii, 1853, 69 ; P.Z.S., 1852 

 (1854), 57. H. (Charopa) iota, Pfr. : Hector, Cat. Land Moll. N.Z., 8. 

 Patula iota, Pfr. : Hutton, M.N.Z.M., 6. P. (Charopa) iota, Pfr., Nomencl. 

 Hel. Viv., 97. Charopa (Thalassia) iota, Pfr. : Tryon, Man. Conch. (2), 

 ii, 212, pi. 62, f. 43. Phenacohelix granum, Pfr. : Hedley and Suter, 

 P.L.S. N.S.W. (2), vii, 642 ; not of Pfeiffer. 



Shell very small, globose, perforated, thin and fragile, not shining, 

 finely costate. Sculpture consisting of fine microscopic spiral striae 

 on the protoconch and all the other whorls, close and fine radial riblets 

 on the post-nuclear whorls, about 9 per millimetre, but in some speci- 

 mens only 8 or 7 are present ; the interstices microscopically finely 

 decussated; the riblets are straight above, slightly sinuatcd on the 

 periphery and base. Colour yellowish-horny, with rufous spots on 

 the upper surface, faint reddish zigzag lines on the periphery and base. 

 Epidermis thin, translucent. Spire shortly conoidal, outlines convex, 

 its height about two-thirds that of the aperture. Protoconch of 1 

 whorls, the nucleus slightly elevated. Whorls 5, rather convex, 

 gradually increasing, the last not descending, rounded. Suture im- 

 pressed. Aperture a little oblique, rotundly lunar. Peristome simple, 

 straight, margins distant. Columella short, arcuate. Inner Up slightly 

 thickened, but slightly reflexed above. Umbilicus narrow, deep, ai- 

 ways open, its diameter about 0-5 mm. 



