GASTROCOPTA, POLYNESIA. 143 



The upper palatal plica is tuberculiform, small, the lower 

 lengthened. There is no basal plica, or in some specimens a 

 slight thickening may be made out with difficulty. 



The figured specimens measure 2.4x1 mm. (fig. 1) and 

 2.6x1 mm. (fig. 2). 



Specimens from the "coral bluff" west of Kahuku, at the 

 northwest end of Oahu, are typical. The smallest measured 

 is 2.2 mm. long, 0.95 diam. ; others being up to 2.65 mm. long. 

 Several thousand were collected there in a few minutes, in the 

 surface debris. 



The shells from the hotel grounds, Haleiwa, on the west 

 coast, and those from the bluff at Kawaihapai, near the south- 

 west point of Oahu, differ by the reduced size of the upper 

 palatal, which is extremely small in some, wholly wanting in 

 most of the specimens. The size varies from typical to a 

 smaller, short-whorled form, one of which from Kawaihapai is 

 figured (pi. 24, fig. 4, 2.35 mm. long). 



Specimens taken in a very arid place on the railroad above 

 Watertown, East Loch of Pearl Harbor, average small, with 

 the palatal plicae small, upper and basal minute, subequal, the 

 lower palatal short (pi. 24, fig. 3). 



Form kailuana. PL 24, figs. 5, 6. On the north (Koolau or 

 windward) side of Oahu, at Kaelepulu, Kailua, it was found 

 in copious quantity on old reef rocks not far inland. Here 

 there is a tubercular basal fold distinctly developed, often 

 larger than the upper palatal, which in some specimens is very 

 small or even wanting. In size they do not differ from the 

 Manoa and Kahuku shells. 



Philippine Records. Dr. von Moellendorff (1893) states 

 that Professor Boettger communicated to him the opinion that 

 he would retain Pupa artensis Montr, as a species distinct 

 from pediculus on account of its slimmer, nearly cylindric 

 shape. "Besides, in New Caledonia the glossy-clear type 

 occurs; also on Luzon, where my friend O. Hennig found it 

 on the cliffs Pena blanca, Province Cagayan." In his Ver- 

 zeichniss, 1898, he gives the localities "Cebu, Bohol, Luzon, 

 etc." In my opinion, the shells in question are not really 

 artensis, but a form of lyonsiana. 



