SuTER. — On Neiu Zealand MoUusca. 297 



its cutting-point to the posterior end of it. Side-cusps rounded, 

 with one small cutting-point on each. 



Laterals like the central, but slightly asymmetrical, more 

 so on approaching the marginals, base slightly broader; reflec- 

 tion triciispid, the median cusp somewhat longer than in the 

 central, its cutting-point reaching over the following row of 

 teeth; side-cusps sinuated, the inner with a rather strong 

 cutting-point, the outer with a very small one only. 



Marginals much broader than long, first tridentate, in the 

 twelfth to the fourteenth there are usually four denticles on 

 each ; the last has a very narrow base, with a minute denticle. 



Phrixgnathus glabriuscula, Pf. From Mount Wellington, 



near Auckland. Plate XXII., figs. 38, 39. 



Jazo arcuate, consisting of about 20 broad slightly imbri- 

 cating plaits, which are papillate. Both margins denticulated, 

 the denticles of the cutting-margin fringed by the papillae. 



Radicla. — Transverse rows of teeth curved, with the rows 

 of marginals directed forwards. Teeth, 26 — 1 — 26, of which 

 about 14: are laterals. 



Central tooth rectangular, long and very narrow ; reflection 

 unicuspid, with a short cutting-point, both together extending 

 over the anterior third of the base only. 



Laterals rectangular, little longer than broad, bicuspid, the 

 inner cusp with a long oblique cutting-point, reaching to the 

 posterior margin of the base ; the outer cusp with a short 

 cutting-point. 



Marginals quadrate, bicuspid, with two short cutting-points. 



Phrixgnathus transitans, n. sp. Plate XXIL, fig. 40, a, b. 



Shell conoidal, subperforated, finely striated with growth- 

 lines, faintly shining ; colour pale yellow-horn, irregularly 

 banded with chestnut ; transparent, fragile. Spire conoidal, 

 apex rather obtuse. Whorls 5, slowly and regularly in- 

 creasing, rather flattened, the last acutely keeled, striae 

 very delicate, slightly arcuate ; suture not deep, not mar- 

 gined. Aperture vertical, subrhomboidal ; peristome rather 

 thin, angulated ; outer lip strongly callous, the white cal- 

 losity reaching to a good distance in the interior. Colu- 

 mellar margin slightly deflexed, callous, short, regularly 

 arched. Base convex. Umbilicus very narrow, partly covered. 



In young specimens the callosity extends very far back- 

 wards, and the umbilicus is open. 



Diameter, greatest 3mm., least 2^mm. ; height, 2-|mm. 



Hab. Heavy bush, Parua Bay, Whangarei (Ch. T. Musson). 

 Evidently scarce. 



This species is very near Pit. marina, Hutt., but has no 

 lamellse or teeth in the aperture, and the suture is not mar- 



