90 HELIX-MAORIANA. 



Spire very little elevated, nearly flat; apex bare. Whorls 5, slowly 

 increasing, rounded, the last not descending. Suture impressed. 

 Aperture slightly oblique, rotundly lunar, more excavated in the 

 upper part by the penultimate whorl. Peristome straight, acute, 

 margins not convergent, regularly arched, columellar margin 

 descending. Aperture with 13 laminae 1 on the penultimate 

 whorl, 2 on the columella, and 10 on the palatal wall. The plait 

 on the penultimate whorl is central, high, but rather thin, forked at 

 the top by a deep and large groove. The two laminae on the col- 

 umella are stout, with large base, and both tongue-shaped. The 

 plaits on the palatal wall are fine, long, regularly distributed. 

 Umbilicus deep, broad, nearly one-third of the diameter. 



Alt. 1, diam. 1'75 mill. (Siiter.) 



North Island, N. Z., at Hastwell, under rotten wood and bark ; 

 also at Greymouth. 



H. microundnlata SUTER, Tr. N. Z. Inst. 1889, p. 223, t. 14, f. 4a- 

 d. Maoriana microundulata SUT., /. c. 1891, p. 299, t. 23, f. 49, 50 

 (jaw and dentition.) 



P. AORANGI Suter. PI. 24, figs. 48, 49, 50, 51. 



Shell small, depressed, globular, yellowish- white, with somewhat 

 irregular chestnut zig-zag or sinuated streaks, faintly shining, thin, 

 transparent. With well developed ribs, nearly straight, about 38 in 

 the tenth of an inch (15 per mill.). Whorls 5* to 5, slowly increas- 

 ing, rounded. Suture impressed. Aperture slightly oblique, 

 rotundly lunar, regularly excavated by the penultimate whorl. 

 The last whorl not descending. Aperture straight, acute, margins 

 slightly convergent; columellar margin descending, not reflected. 

 Aperture with 12 laminae 1 on the penultimate whorl, 2 on the 

 columella, and 9 on the palatal wall. The lamina on the penul- 

 timate whorl is a little above the centre, high, rather thin, and 

 forked by a deep and broad groove. The two laminae on the col- 

 umella are stout, with large base, and tongue shaped, the first rather 

 sharp. The nine lamellae on the palatal wall are fine and loug- 

 the five lower ones a little stouter, and separated from the four upper 

 by a somewhat larger interval. Umbilicus deep, perspective, not 

 very broad, about one-quarter of the diameter. 



Alt. 1-25, diam. 2 mill. (Suter.^ 



South Island, N. Z. at Hooker Valley; environs of the Mount Cook 

 Hermitage. 



