66 PEOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Plectopylis. It has the parietal callus raised into a flexuous, 

 transverse lamella parallel with the, outer and basal margins of the 

 peristome, which are equally raised, nearly closing the aperture, 

 while there are besides two internal parietal lamellae. 



The subgenus Libera, Garr., occurs only in the Society and 

 Cook Islands. These shells are provided with revolving, entering 

 folds on the parietal wall, and the lower part of the last whorl. 

 E. jacquinoti, H. & J., from Tahiti, is a fairly large species, and 

 possesses two revolving, entering lamellae on the parietal wall, with 

 one low curved fold on the columella and three raised, revolving 

 lamellae on the basal wall of the last whorl.. 



The subgenus Endodonta, s.s., ranges over the Sandwich, Society, 

 and Pelew Islands. E. lamellosa, Fer., a Sandwich Islands species, 

 is provided with no less than eight revolving, raised lamella : two 

 on the parietal, one on the upper, four on the basal, and one on the 

 columellar wall. E. lacerata, Semp., from the Pelew Archipelago, 

 has only one entering lamella on the basal wall midway between the 

 columellar angle and the periphery, one low revolving fold on the 

 columella, while the parietal wall bears three raised ridges and 

 several smaller ones between the latter and the columella, all 

 these ridges being continued outside on the base of the shell as far 

 as the peristome. 



The subgenus Thaumatodon, Pilsbry, with numerous species, is 

 distributed over Polynesia, New Zealand, New Caledonia, Tasmania, 

 and the Philippines. E. multilamellata, Garr., a Cook Islands 

 species, has three revolving lamellae on the parietal wall, three on 

 the basal wall, and one on the columella. E. Jieptaptychia, Q. & M., 

 from Guajam, an island in the Ladrones Archipelago, j)ossesses two 

 revolving, entering, parietal folds ; three raised lamellae on the outer 

 wall, the middle one being largest; three on the basal wall, the 

 middle one smallest ; one on the columella ; all these lamellae are 

 some distance from the peristome. E. tomlini, Gude, another form 

 from Guajam, has, like the former, two parietal folds ; three raised 

 lamellae on the outer wall, the topmost being smallest, and one 

 the basal wall. 



The subgenus Nesophila, Pilsbry, is of Polynesian distribution ; 

 E. tiara, Migh., from the Sandwich Islands, is the largest of all the 

 Endodonts, a full-grown specimen in my possession measuring as 

 much as 14. mm. in diameter ; it has a wide aperture, and is provided 

 with eight or nine low, revolving, entering folds on the parietal wall 

 but without any palatal teeth or lamellae. E. hystrix, Migh., and 

 E. jugosa, Migh., also from the Sandwich Islands, are provided 

 only with one low, revolving, entering fold on the parietal wall. 



The subgenus Ptychodon, Ancey, is a small group of minute 

 species confined to New Zealand. E. hectori, Sut., has five parietal 

 lamellae, the principal one, stout and median in position, being 

 grooved or bifid, the other four smaller and placed between it and 



