52 HELIX POLYMITA. 



defiexed toAvard the aperture ; aperture rounded-lunar, very oblique ; 

 peristome reflexed, thickened, white or flesh-colored, its margins 

 slightly converging. 



Alt. 26, diam. 30 mill. ; alt. 31, diam. 31 mill. ; alt. 17, diam. 24 

 mill. 



Western Cuba. 



R. subtussitlcata WRIGHT, (teste Gundlach in litQ PFEIFFER, 

 Malak. Bl 1863, p. 199 ; I. c. 1864, p. 124 ; Novit. Conch, t. 61, f. 1- 

 3 ; Monographia v, p. 279. ARANGO, Fauna Mai. Cubana, p. 69. 



Quite variable in size and elevation, but instantly known by the 

 deep curved pit upon the base opposite the aperture, which produces 

 a tooth inside, much as in the subgenus Cepolis. H. subtussulcata 

 is nevertheless a genuine Jeanneretia. 



Group XII. POLYMITA Beck. 



On account of the peculiar dentition of the snails of the section 

 Polymita, I think it is entitled to rank equal with the other divisions 

 called Groups in this work. The shells are quite similar to those 

 of Hemitrochus in general aspect ; but they have simple, not expand- 

 ed peristome, and fewer, more rapidly enlarging whorls. The colora- 

 tion is scarcely equalled for brilliancy and beauty among all the land 

 shells. All of the species are Cuban. 



I am inclined to attribute the gouge-shaped teeth of the radulato 

 the modification effected by fruit-eating habits, for the broad cusps 

 of these Helices would doubtless be more effective than the common 

 narrower, acute type of teeth. The coloration also may be accounted 

 for by assuming it to be a protective adaptation ; for both the yellow 

 and red forms of H. picta are much the color of ripe bananas and 

 other fruits. This way of accounting for the principal characterstics 

 of this group brilliant hues and abnormal, gouge-shaped teeth- 

 although it strikes me as a probable explanation, rests upon very 

 slender foundation of fact ; for all I know of the life-history or 

 habits of the snails in question is derived from Mr. Binney's remark 

 that he had received a specimen found on a bunch of bananas in 

 New York. 



Section POLYMITA Beck, 1837. 



Shell semiglobose or subglobular, rather thin but solid, imperforate, 

 brilliantly painted ; whorls 4 or less, the last slightly defiexed at 

 the aperture; aperture large, rounded, slightly lunate; peristome 



