TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 41 
indication of a keel. Rarely they exhibit slight traces of spiral riblets, but the shallow 
sulcation on the upper surface is not infrequent. Immature shells have usually radi- 
ating, distant, thin, deciduous, lacerated or hirsute membraneous riblets both above 
and beneath. The color is greenish corneous, with small spots and stripes of reddish 
brown. Raiatea examples are more variable than Huaheine specimens. ‘The whorls, 
6-7, are marked by fine, not smooth, strie of growth. ‘The very wide umbilicus is 
more than half the diameter of the shell. ‘The base of the last whorl is either rounded 
or slightly angulated, and the aperture is subcircular in full-grown shells or subrhom- 
boidal in immature examples. 
H. CRETACEA, Garrett. Plate II, figs. 27, 27 a, 27 b. 
Pitys ficta, Garr. (not of Pease). Schmeltz, Cat. Mus. Godeff., v, p. 223 (ex. Garr.). 
Shell very broadly umbilicated, rather solid, depressed, lenticular, finely striated, 
dull whitish, with small, irregular, scattered brown spots; spire depressed convex, or 
subplanulate, with flat outlines; apex subacute; suture linear; whorls 64-7, planu- 
late, narrow, slowly and regularly increasing, the last two slightly concave, acutely 
carinate on the periphery, not descending in front; beneath the keel oblique, planu- 
late; base acutely angulate; umbilicus very large, funnel-shaped, with planulate 
walls; aperture oblique, quadrate; parietal region with a single revolving lamina, and 
one in the throat between the keel and basal angle ; peristome simple, acute, straight ; 
columella simple. 
Major diam. 6, height 2 mill. 
Hab.—Borabora Island. 
Common, but very local and restricted to the above island, where they live on the 
ground in forests at an altitude of about 600 feet above sea-level. 
It is shaped and colored nearly the same as fabrefuctu, but is smaller, more 
depressed, and the last whorl is not so deep, and the flattened space between the two 
angles is more oblique. They also differ in the outlines of the spire, and the two 
internal laminw are constant. 
Many of the adult shells have the umbilicus covered with a thin brownish yellow 
membrane, which, in all I examined, was perforated. Probably the animal, as in 
Libera, oviposits into the umbilicus and covers the opening with the membrane, and 
the perforations were made when the young escaped I searched, in vain, for intact 
membranes in hopes of discovering either the eggs or young shells. This peculiar 
feature has, so far, only been observed in the Borabora shells. I copy the following 
from the Jour. de Conch., 1865, p. 395 :— 
“1,Endodonta lamellosa, Fér., dépose ses ceufs dans l’ombilic, ainsi qu'une autre 
espéce des iles Sandwich communiquée par M. Harper Pease: dans cette derniére 
Vombilic était couvert dune sorte d’épiphragme” (O. A. Morch). 
