TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 
97 
scitula. The shape is oblong-conical, rimately peilorated, whorls six, moderately 
convex, margined by a thread-like keel, which latter is very conspicuous on the sub- 
angulate body-whorl. The base is more or less compressed on the margin of the 
perforation. Nearly all my examples are decorticated and have a whitish or yellowish 
aperture. The general color is pale corneous or pale fulvous. 
The peristome is slightly expanded at the base and over the perforation, and the 
margins united by a deposit of callus. 
Color variable ; whitish, corneous, fulvous, brownish, ruddy brown, rarely pale 
luteous. Aperture concolored, sometimes ochraceous. The thin brownish epidermis 
is rarely present on adults. The striae of growth are scarcely visible under a strong 
lens. 
Genus ATROPIS, Pease. 
The above genus was instituted by Mr. Pease (Proc. Zool. Soc., 1871, p. 463) for 
the reception of those species of OmpJialotropis which are devoid of the basal carination. 
Although he ranked the eliminated group as subgeneric, in the same paper (p. 476) 
he used the name in a generic sense and records eighteen species. His “A. affinw ” 
is, by Von Martens, Paetel, Schmeltz and myself, referred to the genus Scalinella. 
His “A. ochrofitrema ” has, like Omphalotropis Hnaheinensis, a more or less obsolete 
keel and should be transferred to that genus. His “A. insularis,” and probably A. 
exigiio, are Chondrellce. 
After eliminating all the Society Islands species of the scihda and terehndis type 
there remain several species which are nothing more than smooth ScaUnellcB. 1 hese 
only I retain under the name of Atropis, and it may be characterized as follows 
Shell small, rimate or minutely perforated, ovate-conic or elongate-conical, smooth ; 
whorls rounded, suture profound, body-whorl usually turgid ; aperture subciicular , 
peristome simple, sometimes indistinctly duplex, continuous and briefly adhering to 
the penultimate whorl. 
A. ABBRKVIATA, Pease. 
Realia abbreviaia, Pease, Proc. Zool. Soc., 1864, p. 614. Pfeiffer, Mon. Pneuin., iv, p. 212. 
Omphalotropis abbreviata, Pease, Jour, de Conch., 1869, p. 155, PI. VII, fig. 5. 
Atropis abbreviata, Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godeff., v, 
p. 102. 
A ,ome«hat rare species, found on the ground on the northwest side of Tahiti. 
It may be distinguished by its oblong-ovate form, rounded whorls and yentrieose 
body. The axis is subperforated or rimate and the apex rounded. Under the 
brownish or olivaceous epidermis tlie shell is pale horn-color, rarely light olive or 
ruddy corneous. The aperture is concolored or pale yellowish brown. 
