92 TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 
Laimodonta conica, Martens and Langk., Don. Bism., p. 57, Pl. Tess: 
Plecotrema Anaaensis, Paetel, Cat. Conch., p. 114. 
Melampus conicus, Pfeiffer, Mon. Pneum., iv (Auriculacea), p. 319. 
’ Melampus Anaaensis, Pfeiffer, 1. ¢., p. 320. 
This species, though ranging from the Paumotu to the Viti Islands, is rarely found 
in the Society group. It is smaller and not so robust as L. Bronni of the Sandwich 
Isles. The spiral impressed lines are more conspicuous, and the aperture exhibits a 
heavier deposit of callus in the palate. 
Genus PLECOTREMA, H. and A. Adams. 
P. Morpax, Dohrn. 
Plecotrema mordaz, Dohrn, Mal. Blat., 1859, p. 204. Pease, Jour. de Conch., 1871, p. 93. 
Martens and Langk., Don. Bism., p. 55, Pl. IIL, fig. 8. Paetel, Cat. Conch., p. 114. 
A few dead specimens found on the seashore on the northeast coast of Tahiti. It 
is not uncommon on the Paumotu Isls. 
The examples now before me are more globose than any Polynesian species known 
to me. ‘he riblets aré rounded and rugose. My specimens average from 5 to 6 
mill. in length, and are nearly white with a very broad, light fulvous zone. 
Genus DIADEMA, Pease. 
Amer. Jour. Conch., 1868, p. 158. 
Garrettia, O. Semper, Cat. Mus. Godeff., vy, p. 100, 1874. 
D. BIANGULATA, Pease. Plate IT, fig. 29. 
Cyclostoma biangulata, Pease, Proc. Zool. Soc., 1864, p- 674. 
Diadema biangulata, Pease, Proc. Zool. Soc., 1871, p. 475. Pfeiffer, Mon. Pneum., iv, p. 56. 
Garrett, Jour. Acad. Nat. Sci. Phila., 1881, p. 404. 
Cyclophorus (Ostodes) biangulatus, Martens and Langk., Don. Bism., p. 58, Pl. III, fig. 16. 
Garrettia Scalariformis, Paetel, Cat. Conch., p. 424. 
Garrettia biangulata, Schmeltz, Cat. Mus. Godeff., v, p. 100. 
? Cyclophorus biangulatus, Pfeiffer, Mon. Pneum., iv, p- 114. 
? Cyclomorpha biangulata, Pfeiffer, 1. ¢., p. 234. 
A few examples were found under decaying leaves and confined to a small area on 
the southwest side of Moorea, where I obtained Mr. Pease’s type specimens. The 
metropolis or specific centre of this species is Aitutake, one of the Cook’s or Harvey 
Islands, where it is found in the greatest profusion. 
Its conical shape, brown color and tricarinate body-whorl will readily distinguish it. 
Genus OMPHALOTROPIS, Pfeiffer. 
This genus was established by the above author for the reception of a group of 
cyclostomoid shells, which are distinguished by the filiform carina which circumscribes 
the basal perforation, simple or slightly expanded peristome, and in shape varying from 
globose-turbinate to elongate-conical. 
