49G THE LAND AND FRESH-WATER MOLLUSCA OF NEW ZEALAND, 



Jaw very thin, membranaceous ; the upper margin arcuate, the 

 cutting edge indistinct, almost straight, running over into the 

 membrane to which jaw and radula are attached. 



Radula tongue-shaped, the transverse straight rows consisting 

 of 16 — 1 — 16 teeth, of which 4 to 5 may be considered as laterals. 

 In another radula the formula was 15 — 1 — 15. Central tooth 

 quadrangular, longer than broad, sinuated anteriorly, reflection 

 tricuspid, the median long and reaching with its short cutting 

 point to the posterior end of the base ; the side-reflections are 

 short, rounded, each with a rudimentary cutting point. Laterals 

 broader, almost quadrate, similar to the rachidian tooth, but the 

 median cutting point is extending beyond the base over the next 

 row of teeth. A few intermediate teeth show a shortening of the 

 median reflection, its cutting point growing stouter and longer, 

 and the cutting point on the inner side is also increasing in size. 



Marginals short and very broad, first with three, then with four 

 teeth, of which the two inner ones are long and stout, the outer 

 ones remaining small. Last marginal minute, quadrate, with two 

 teeth. 



Charopa segregata, n.sp. 

 (PI. xxm. figs. 10-106.) 



Shell small, discoidal, umbilicated, not shining, colour horny 

 with distant, irregular light-brown radiate streaks ; thin, semi- 

 transparent ; rather distantly ribbed, the ribs almost straight, 

 extendirig to the umbilicus ; about 5 per millm., interstices with 

 numerous very fine growth-lines. Spire flat, apex smooth, some- 

 what shining, white. Whorls 5, slowly and regularly increasing, 

 rounded, the last not descending in front ; suture impressed, 

 periphery rounded. Aperture slightly oblique, rotundly-lunar, 

 but little excavated by the penultimate volution. Peristome 

 simple, acute, straight ; columellar margin arcuated, not reflexed, 

 margins slightly converging. Umbilicus broad, conical, about 

 one-third of the diameter ; base rounded. 



Diam., greatest 2|, least 2| ; height \\ millm. 



