TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 
37 
the columella, two short conspicuous ones in the palate between the keel and base, 
and a less conspicuous one above ; peristome thin, straight, the lower margin contin- 
uous with the umbilical constriction ; columella short, concave, receding. 
Major diara. 51, height 21 mill. 
Hah. — Moorea. 
Very abundant beneath decaying vegetation, and restricted to the louder part of 
one valley on the west side of Moorea, and the only species found in tliat location. 
The deflection of the last whorl below the periphery of the penultimate wdiorl, 
which is an accidental character in some of the species, is constant in this. The per- 
sistence of this feature, together with the fine, crowded striae, dark color, absence of 
concentric lines, as well as difference in the internal laminae, are its most essential 
characters. 
Genus ENDODONTA, Albers. 
This genus was instituted by Dr. Albers for a peculiar group of small Helices 
inhabiting the Sandwich Islands, the type of which is Helix lamellosa. For. Five 
species are known to inhabit that group ; all of which are characterized by their len- 
ticular form, acutely carinate periphery, large umbilicus, subrhomboid or securiform 
aperture, which is garnished with two parietal, one columellar, and three or four 
palatal laminae. 
Some of the Society Islands species are very closely related to the Sandwdcli Islands 
shells in shape, and the existence of one or more deeply seated lamina' in the palate ; 
the latter character was overlooked by Pfeiffer, Pease, and the writer, when describing 
the different species inhabiting the group. 
They are all very widely umbilicated, the last whorl carinated or angulate, and all, 
with one exception, have one or two parietal lamina? ; the low'er one, when two are 
present, is always shorter, and owing to its being deeply seated has hitherto been o\ er- 
looked. The aberrant species are Helix fabrefacta. Pease, which is without lamina', and 
H. ololus, Gould, which has a single one on the parietal region ; otherwise the shaiK? 
of the shells is quite similar to the others. The laminae are not so prominent as in 
the typical species, and are distinctly represented in the different stages of growth, 
but, excepting those on the last two whorls, are gradually absorbed by the animal. 
They inhabit aU the Islands except Tahiti and Moorea, where they are represented 
by a distinct group of Helices, the type of which is Helix Imrsatella, Gould. They 
are all ground species, and are very numerous in certain favorable localities. 
E. IltJAHEiNENsrs, Pfeiffer. Plate II, figs. 26, 26 a, 26 b, 26 c. 
Helix Huaheinensis, Pfeiffer, Zeit. Mai., 18.53, p. 55 ; Mon. Hel., iii, 640. 
Endodonta Huaheinensis.! Pfeiffer, Yers., p. 129. Albers, Die Hel.,ed. 2, p. 9. Pease, Proc. 
"Zool. Soc., 1871, p. 474. Paetel, Cat. Conch., p. 91. 
Patula HuaheinensiS! Schmeltz, Cat. Mus. Godeff., v, p. 93. 
This species is abundant in all the large valleys on Huaheine. Though widely 
6 JOUK. A. N. S. PHILA., VOL. IX. 
