386 THE TERRESTRIAL MOLLUSCA INHABITING 



It can easily be distinguished by its large size, perfectly flat spirfe, large open 

 umbilicus, fine crowded rib-like striae, and profound suture. 



P. Atiensis, Pease. 



Pithys Atiensis, Pease, Jonr. de Conch., 1870, p. 394. 



Pitys Atiensis, Pease, Proc. Zool. Soc, 1811, p. 453, 414. 



Patula vicaria, Mousson, Jour, de Conch., 1811, p. 11, PL 3, fig. 2; 1813, p. 104. Schmeltz, Cat. 



Mus. Godeff., v. p. 93. 

 Helix vicaria (Patula), Paetel, Cat. Conch., p. 96. 

 Patula modicella, Schmeltz (Ferussac?), Cat. Mus. Godeff., v. p. 93. 

 Helix Atiensis, Pfeiffer, Mon. Hel., vii. p. 165. 

 Helix vicaria, Pfeifi"er, Mon. Hel., vii. p. 181. 



I obtained Pease's type specimens in a forest near the sea-shore at Atiu, where 

 it was abundant. It also occurred, but more sparingly, at Aitutaki, and subse- 

 quently I took hundreds of examples in diff'erent parts of Rarotonga. 



Specimens from the latter location attain a larger size than mentioned by 

 Pease, and vary slightly in the size of the umbilicus, and some have the spire 

 more elevated than others. 



The color is also somewhat variable. 



After a careful comparison with Mousson's vicaria, I fail to note a single dis- 

 tinguishing character to separate the two shells. The shape, coloration, sculpture, 

 and variation are precisely the same, and, except in color, can scarcely be separated 

 from the Tahitian modicella. 



Mousson's vicaria, collected by Dr. Graffe, is widely diffused through Tonga 

 and the Ellice group of islands. 



Undetermined examples of Atiensis, sent to the Museum Godeffroy, were 

 referred, part to vicaria and part to modicella. 



P. PROXiMA, Garrett. 



Pitys proxima, Garr., Araer. Jour. Conch., 1812, p. 230, PI. 19, fig. 24. 



Patula proxima, Schmeltz, Cat. Miis. Godeff., v. p. 93. 



Helix proxima, Pfeiffer, Mon. Hel., vii. p. 543. 



Not uncommon in several valleys on Rarotonga. It is most nearly allied to 

 the preceding species, but may be distinguished by its much smaller umbihcus, 

 deeper suture, and more particularly by the peculiar angular emargination on the 

 upper portion of the peristome. A few examples were found of an uniform deep 

 black color. 



