30 TKimESTBIAL MOLLUSCA INHAEITINfi SOCIETY ISLAEUS. 
Sliipci, will, che.n„l-w,i. Tl.e ,evo.vi„, slri. lu-e sometime, „..a..y 
obsolete. 
Diam. o-5|, height 2i-3| mill. 
L. OREUAKiA, Garrett, Plate II, figs. 6, 6 a, 6 &. v.' ' itr elrmelv and 
Sholl small, umbilicatcd, solid, ™ 
ol,li,,„cly striated with smaU, regular, slightly b.arcuate, rough ^ restnut- 
cwled on the base- whitish corneous, tesseUated and undulately rayed with the.stnut 
brown; spire depressed dome-shaped, apex flattened; suture ' 
whorls seven, slightly convex, narrow, slowly and rcgularlj incieasi e . 
earinated, sometimes descending a little below the penultnnate who 1 , base fla ly 
convex, .-oncave on the boundaries of the umbilicus; umbilicus (m 
exposing all the whorls, one-third the major diameter of the shell ; m adults stio „ y 
eonstricLl by an acute expansion of the last whorl; aperture small, ohln.ue, 
depressed, irregular rhomboid-luniform ; laniinte 0-6, two in the parieta repoli, 
elongate, of equal length, one columellar, two in the palate beneath the keel, 
short ronspicuons, one above the keel, inconspicuous and occasionally absent ; peris- 
tome acute, straight, basal margin continuous with the acute umbilical constriction; 
columella short, concave, receding. 
Major diam. 7, licight 85 mill. 
Hdh. — Moorca. 
I discovered two colonies of this very distinct species in two valleys on the south- 
west iiart of Moorea. They were congregating in immense numbers on the under side 
of loose stones. 'I’liough carefully searched for, I failed to detect them in any other 
part of the island. No other species of this genus occurs in the same location witli 
tlie shells under consideration. 
M’ith the exception of a slight difference in the elevation of the spire, they arc 
very uniform in all their specific characters. 
L. RECEDENS, Garrett. Plate II, fig. 7. 
Shell small, umbilicated, not shining, rather solid, depressed, orbicular, with thin, 
crowded, slightly oblique, rough, elevated striae, which are finer and more close!)’ set 
on the base; dark chocolate-brown, with or without yellowish horn-colored tessellations 
and undulated stripes ; spire depressly convex, apex flattened ; suture linearly 
impressed ; whorls seven, very little convex, narrow, slowly and regularly increasing, 
last one earinated, gradually descending below the periphery of the penultimate 
wliorl ; base convex, concavely indented at the axis ; umbilicus (in adolescence) freely 
exposing all the whorls, a little more than one-third the greater diameter of the 
sliell ; in adults the umbilicus is constricted to about one-third that of adolescent 
examples ; aperture small, depressed, oblique, irregularly rhomboid-luniform ; laminae 
six, two on the parietal region, elongate, the lower one deeply seated, a stout one on 
