THE COOK'S OE HARVEY ISLANDS. 387 



P. RUDis, Garrett. 



Pitys rudis, Garr., Amer. Jour. Conch., 1872, p. 227, PI. 19, fig. IS. 



Patula rudis, Schmeltz, Cat. Mus. Godeff., v. p. 93. . 



? Patula sublaminata ("Mouss."), Schmeltz, Cat. Mus Godeff., v. p. 94. 



Selix rudis, Pfeiffer, Mon. Hel., vii. p. 541. 



A very abundant species, peculiar to Rarotonga, where we gathered hundreds 

 in several valleys. 



I know of no species with which it is likely to be confounded. It can easily 

 be recognized by its rude, irregular, sharp, rib-like striae, which are more or less 

 deciduous, dark-brown color, small umbilicus, and the slight concave depression 

 on the declivous body whorl. 



P. DECORTicATA, Garrett. 



Pitys decorticata, Garr., Araer. Jour. Conch., 1812, p. 228, PI. 19, fig. 19. 



Pitys Otareae, Garr., Amer. Jour. Conch., 1812, p. 288, PI. 19, fig 21. 



Patula decorticata, Schmeltz, Cat. Mus. Godeff., v. p. 93. 



Patula Otarese, Schmeltz, Cat. Mus. Godeff., v. p. 94. 



Helix decorticata, Pfeiffer, Mon. Hel., vii. p. 592. 



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



This, which is the most abundant species found on Rarotonga, is, so far as I 

 could ascertain, confined to two valleys, which are about three miles apart; one 

 occupied by the type, and the other by the variety Otarece. 



As compared to canalis it is smaller, the umbilicus less open, the ribs larger, 

 rougher, and more distant. The sutural line is also less profound and the color 

 different. 



After a careful study of numerous examples of decorticata and Otarece, I have 

 decided the two to be specifically the same, though the latter may be retained as 

 a permanent variety, characterized by its uniform deep brown-black color. The 

 former is a little larger, usually decorticated, and much lighter colored; but in 

 shape, size of umbilicus, and sculpture differs none from Otarece. 



P. Harveyensis, Garrett. 



Pitys Harveyensis, Garr., Amer. Jour. Conch., 1812, p. 228, PI. 19, fig. 20. 



Patula Harveyensis, Schmeltz, Cat. Mus. Godeff., v. p. 93. 



Helix Harveyensis, Pfeiffer, Mon. Hel., vii. p. 542. 



Not uncommon, and peculiar to Rarotonga. It attains a little larger size than 

 the preceding, and may be distinguished from that species by its smaller and more 

 crowded riblets and different color. In shape and markings it is very closely 

 allied to Patula complementaria, a Samoa species, but quite different in the style 

 of sculpture. 



