HELIX-ENDODONTA. 85 



species differs in the greater number of teeth and the much finer 

 striation. 



This species, with the next two, forms a group intermediate 

 between the toothed Endodonta and the toothless Charopa. 



P. JESSICA Button. PL 24, figs. 24, 25, 26, 27. 



Shell small, discoidal, widely umbilicated, ribbed ; color horny, 

 largely radiately streaked and clouded with reddish-brown, giving 

 a general dark color to the shell. Spire flat or slightly convex, 

 apex often pushed in; whorls 4 to 5J, very slowly increasing, 

 rounded, with numerous rather close ribs, which are strongly sinu- 

 ated on the upper surface, but straight and feebler below ; ribs about 

 36 in 'the tenth of an inch, the interstices strongly striated with 

 growth-lines, and more or less reticulated with spirals; suture 

 impressed; umbilicus wide, perspective, showing all the whorls ; aper- 

 ture nearly vertical, rotundly lunar; peristome thin, flatly angled 

 above, then regularly arched, the margins at right angles. 



Greatest diameter '17, least '15, alt. '08 inch. (Hutton.*) 



Bealey, Canterbury, New Zealand. 



Patula Jessica HUTTON, Tr. N. Z. Inst. xvi, p. 174. 



P. CRYPTOBIDENS Suter. PL 24, figs. 28, 29, 30, 31. 



Shell very minute, discoidal, umbilicated, cinereous, not shining, 

 very fragile, subtransparent, with very fine and extremely close-set 

 ribs, which are slightly bent forward, but almost straight on the upper 

 surface, and rather sinuated at the periphery, about 85 to 90 in the 

 tenth of an inch (35 per mm.). Spire flat. Whorls 4J, narrow, 

 rounded, regularly increasing, the last not descending. Suture deep, 

 aperture rotundly lunate, subvertical, slightly excavated by the 

 penultimate whorl. Peristome acute, somewhat flattened at the 

 base, the upper margin advancing. Interior of the aperture with 

 two teeth. There is a callosity on the basal margin, from which to 

 the left rises a stout conical tooth ; another tooth of the same shape 

 is near the middle of the parietal wall. Both teeth are at some dis- 

 tance from the margin. Columellar margin short, arcuated, slightly 

 reflected. Umbilicus broad, perspective, showing all the whorls, 

 about one-third of the diameter. (Suter.) 



Alt. 0-75, diam. 1-75 mill. 



White Horse Hill, Hooker Valley, South I., New Zealand, among 

 mould in the subalpine bush. 



