200 PARTULA, MOOREA. 



more slender shape, heavier substance, and wider lip, which 

 is calloused within. P. clara also is an allied species of 

 broader contour, but with an aperture much like that of 

 attenuata. 



In a lot or three specimens sent many years ago by Pease, 

 the suture has a grayish margin ; but in all other shells seen, 

 the margin is white, by loss of the cuticle, or by its becoming 

 permeated with air. Normally the lip-edge and parietal 

 callus are thin, but in one very old shell before me, both are 

 considerably thickened. 



Pease described this species twice, evidently from the same 

 examples. He seems to have forgotten the description of 

 1864. It is an error other prolific authors have committed. 



"When we take into consideration its peculiar habit of 

 concealment in the tops of trees, and its range restricted to 

 the more elevated portions of the valleys, so contrary to the 

 habits of other species, it is really remarkable to find it in- 

 habiting two remote islands, especially as all the other species 

 have a very limited range. It does not occur at Tahaa, which 

 is only four miles from Raiatea, and enclosed in the same en- 

 circling reef. It is no less singular to note its absence from 

 Huaheine and Moorea, though at the former island we find 

 the closely allied P. annectens." (Garrett). 



2. Moorean Partula. 



Four species and numerous subspecies are peculiar to 

 Moorea, which is separated from Tahiti by a channel only 

 eight miles wide. All show clear traces of a common ancestry 

 with Tahitian forms, though since the separation of the islands 

 there has been specific divergence. The affinities of the snails 

 are as follows : 



Tahiti. Moorea. 



P. otaheitana P. mooreana 



P. nodosa P. suturalis 



P. filosa P. tceniata group. 



18. P. MOOREANA Hartman. PI. 29, figs. 17-20. 



The shell is sinistral, deeply 'but shortly rimate, rather thin ; 



