

Endodonta.] GASTROPODA. 719 



sometimes vanishing on the base. Spire very little elevated, broadly 

 convex. Protoconch of 1 convex volutions. Whorls 5, slowly in- 

 creasing, convex, periphery arid base rounded. Suture not deep. 

 Aperture rotundly lunate, slightly oblique. Peristome acute, thin, 

 retracting on the suture and forming a distinct sinus. Columella 

 vertical, short, arcuate. Inner lip slightly thickened, not reflexed ; 

 parietal wall with' a thin shining glaze. Umbilicus wide, about one- 

 third of the greatest diameter, deep, showing all the whorls. 



Diameter Maj., 3 mm. ; min., 2-6 mm. : height, 1-5 mm. 

 Animal unknown. 



Type in my collection. 



Hob. North Island : Auckland ; Forty-mile Bush, type (H. S.). 

 South Island : Kenepuru (McMahon). Under rotten logs and dead 

 leaves ; rare. 



20. Endodonta mutabilis, Suter, 1891. Plate 9, figs. 19, a, b. 



Patula mutabilis, Sut., T.N.Z.I., xxiii, 1890 (1891), 84, pi. 16, f. 2, a, 6, 

 B, C. P. (Charopa) mutabilis, Sut. : Filsbry, Man. Conch. (2), viii, 101, 

 pi. 19, f. 25-27. Charopa mutabilis, Sut. : Hedley and Suter. P.L.S. 

 N.S.W. (2), vii, 656. Endodonta (Charopa) tau, Ph., J. de Conch., xli, 

 267. Charopa tau, Pfr. : Suter, P.L.S. N.S.W. (2), viii, 499 ; not of 

 Pfeiffer. Endodonta (Charopa) mutabilis, Sut. : Murdoch, P. Mai. S., 

 iii, 322. 



Shell very small, subdiscoidal, umbilicated, finely and distantly 

 costate, horny with brown streaks. Sculpture : Protoconch finely 

 and closely radially striate, the following whorls with distant very 

 thin and sharp riblets, 6 to 8 per millimetre, acutely protractive on 

 the upper surface, arcuate toward the periphery, on which and on the 

 base they are almost straight, slightly flexuous ; interstices with 

 numerous fine growth-lines and indistinct dense microscopic strife, 

 absent on the protoconch. Colour horny with irregular light-brown 

 blotches, forming zigzag lines on the periphery, and vanishing upon 

 the base. Spire slightly elevated, flat. Protoconch of 1| convex 

 whorls. Whorls 5, convex, slowly but regularly increasing, the last 

 slightly descending ; periphery and base convex. Suture deep. 

 Aperture oblique, lunate. Peristome thin and sharp, retractive to- 

 ward the suture, where it forms a deep and narrow sinus. Colu- 

 mella vertical, short, arcuate. Inner lip not reflexed, slightly callous ; 

 parietal wall with a thin shining callous layer. Umbilicus wide and 

 deep, showing the micleus distinctly, about one-third of the greater 

 diameter. 



Diameter Maj., 3mm. ; min., 2-6 mm. : height, 1-5 mm. 



Jaw finely vertically striated, arcuate, not tapering at the ends, 

 with a slight median projection. 



Radula having the formula 16 + 1 + 16 ; laterals about 7. Central 

 tooth tricuspid, with a long mesodont ; laterals very similar to the 

 central tooth ; mrrginals with 3 to 4 cutting-points. 



