648 GASTROPODA. [Pulmoriata. 



not shining. Spire slightly elevated, convex, about half the height 

 of the aperture. Protoconch of 1^ convex whorls. Whorls 6, convex, 

 gradually increasing, the last not descending, slightly flattened outside 

 the suture ; base flatly rounded, impressed in the middle. Suture 

 well impressed. Aperture vertical, elongately lunar. Peristome simple, 

 acute, convex. Columella short, oblique. Inner lip with a white 

 callus, reflexed, covering the umbilical tract, spreading broadly as a 

 thin white and shining glaze over the convex parietal wall. 



Diameter Maj., 6 mm. ; min., 5 mm. : height, 3 mm. 



Dentition. Hutton, T.N.Z.I.. xvi, 165, pi. 11. f. Y. 



Jaw arched, with about 10 flat ribs in the centre, the ends striated. 



Radula with the formula 11 + 6-1-1 + 6+11. Central tooth tricuspid, 

 with a long mesodont and small lateral cutting-points. Laterals like 

 the central, but broader, the entocone larger than the ectocone. 

 Marginals with 3 cutting-points, the entocone and mesocone coalesced 

 into a bidentate strong point, the last marginal bidentate. 



Type in the British Museum. 



Hob. Western slope of Mount Cook (Filhol) ; Greymouth (R. 

 Helms) ; Capleston (Cavell). 



16. Allodiscus wairoaensis, Suter, 1894. Plate 25, fig. 18, a, b. 



Allodiscus wairoaensis, Sut. : P.L.S. N.S.W. (2), viii, 488, pi. 22, f. 3, a, 6. 

 Flammulina (Allodiscus) wairoaensis, Sut., Man. Conch. (2), ix, 15 ; 

 Suter, J. de Conch., xli, 253. 



Shell very small, subdiscoidal, perforated, rather distantly radially 

 costate. thin, not shining, semitransparent. Sculpture : Protoconch 

 microscopically distinctly spirally striated ; the following whorls with 

 sharp radiate riblets, about 7 per millimetre, sinuated at the peri- 

 phery ; interstices with fine growth-lines, reticulated by microscopic 

 spiral lirae. Colour pale-horny with radiate streaks of rufous above, 

 tessellated on the periphery, and minutely spotted on the base. 

 Spire depressed, flatly convex, about one-third the height of the 

 aperture. Protoconch of 1^ convex whorls. Whorls 4|, rounded, 

 slowly and regularly increasing, periphery convex ; base convex, im- 

 pressed in the centre. Suture impressed. Aperture slightly oblique, 

 lunar, considerably excavated by the penultimate whorl. Peristome 

 straight, acute, regularly convex, margins very little approximating. 

 Columella short. Inner lip obliquely arcuate, slightly callous, re- 

 flexed above, extending broadly as a thin white layer over the convex 

 parietal wall. Perforation very narrow, quite open in young specimens, 

 but sometimes partly covered by the inner lip in adult examples. 



Diameter Maj., 3-25 mm. ; min., 2-75 mm. : height. 2mm. 



Animal unknown. 



Type in my collection. 



Hob. Wairoa Gorge, Nelson (Meeson). 



Remarks. This species is nearest to A. venulatus, but it is much 

 smaller, perforated, and the costse more distant. 



