32 TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 
zigzagged with chestnut-brown; sculpture consisting of radiating, very thin, not 
crowded, subbiarcuate riblets; spire slightly convex, apex flat, suture channeled ; 
whorls five, narrow, rounded, subangulate near the suture, slowly and regularly 
increasing, last one rounded on the periphery; base convex; umbilicus moderate, 
about one-fourth the major diameter of the shell; aperture vertical, narrow, orbicular- 
lunate ; parietal wall with two, and the palate with four (rarely three or five) lamine ; 
peristome thin, straight, with remote margins. 
Major diam. 3, height 15 mill. 
Hab.—Huaheine Island. ; 
A somewhat rare species, confined to a valley on the north end of Huaheine. It 
differs from parvidens in having the riblets much further apart, deeper channeled 
suture and the whorls angulated next to the suture. 
P. PUNCTIPERFORATA, Garrett. Plate IT, figs. 16, 16a, 166, 16e. 
Shell small, perforated, orbicular, depressed, thin, corneous, tessellated above with 
reddish brown, beneath corn-color, or radiately striped with the same hue; striz very 
closely set, thin, rib-like, subarcuated, smaller and more crowded beneath; spire 
convex or convexly rounded; apex planulate; suture deeply impressed; whorls six, 
rounded, narrow, regularly and slowly increasing, last one not descending in front, 
gibbous above; base convex; umbilicus very small, punctiform; aperture vertical, 
narrow luniform; parietal region with two (rarely three), and the palate with from 
four to five laminz, one of which is columellar; besides the lamine there exist parallel 
raised lines both on the wall of the aperture and in the palate; peristome thin, simple, 
with remote margins; columella thickened with callus. 
Major diam. 3, height 1} mill. 
Hab.—Moorea island. 
A few examples were found at the above locality, but not obtained in any other 
part of the group. ‘The minute umbilicus will at once distinguish it from any other 
Society Island species. One specimen is uniform pale horn-color. 
P. Borasorensis, Garrett. Plate II, figs. 18, 18a, 186. 
Shell orbicular, depressed, widely umbilicated, thin, corneous under a light brownish 
epidermis; above tessellated, beneath with or without undulating stripes of a dark 
chestnut-brown ; sculpture consisting of small, thin, crowded slightly waved riblets ; 
spire but little elevated, apex flat; suture deeply impressed; whorls seven, convex, 
very slowly increasing, last one subangulate, base convexly rounded ; umbilicus large, 
perspective, exhibiting all the whorls; aperture subvertical, ovate-luniform ; parietal 
region with four and the palate with five or six laminz, peristome simple with remote 
margins. 
Major diam. 5, height 24 mill. 
Hab.—Borabora Island. 
