1870.] NATURAL SCIENCES OF PHILADELPHIA. 25 



have the internal teeth so distinct as to give the aperture a rin- 

 gent appearance. 



Cook's Island examples sent to the Museum Godeffroyanum 

 were erroneously referred to Anton's bilamellata, a species twice 

 the size of this. 



Tornatellina serrata, Pease. 



Lnmellina serrata, Pease, Proc. Zon]. Soe. 1860, p. 439. 

 Tornatellina serrata, Pfeiffer, Mon. Hel. vol. VI. p. 265. 

 Lnmellina Icevta, Pease, Proc. Zool. Soc 1864, p. 672. 

 Tornatellina lavis, Pfeiffer, Mon. Hel. vol. VI. p. 266. 



This species has the same extensive range through Polynesia 

 as nitida. Many years ago I found the same, or a closely allied 

 species on low bushes near the seashore at Guam. 



They, like nearly all the species, are usually found adhering to 

 the under surface of loose stones, dead wood, among decayed 

 leaves, and sometimes on the leaves of low bushes. 



I obtained Mi 1 . Pease's type examples of serrata at Ebon, in 

 Micronesia; and his laevis at Huahine and Tahiti. Mr. Cuming, 

 who received specimens of both specie's, considered them identical. 



After a careful examination of a large number of all ages from 

 the different groups of islands, I find the palatal lamina much 

 more frequently serrated than smooth. They are, in fact, all 

 smooth at certain periods of their growth. 



The description of serrata is somewhat obscure ; that of laevis 

 is more accurate. 



It cannot well be confounded with any other Polynesian spe- 

 cies ; its ovate-conic form, swollen whorls, deep suture, acute 

 columellar tooth, and, more particularly, the remote longitudinal, 

 prominent, smooth, or serrated palatal laminae will readily distin- 

 guish it from an}' other. 



The last character induced Mr. Pease to establish his genus 

 Lamellina. In his list of Polynesian land shells published in the 

 Proceedings of the Zoological Society for 1ST 1 , lie records only 

 two species, his serrata and Isevis, while he overlooked the same, 

 but less conspicuous character in Hidalgoi, Crosse, inhabiting the 

 Gambier Islands. The accurate figure of that species in the 

 Journal de Conchyliologie for 1865, exhibits a small bidentate 

 lamina. Specimens from the same locality, now before me, either 

 possess the same feature, or have simply from one to two spiral 

 rows of denticles in the palate. 

 3 



