44 PROCEEDINGS OF THE ACADEMY OP 



we find in onr S. ajjj^endiculata. His species and ours are there- 

 foi'e distinct. 



Pellicula convexa, Martens (Succinea), is quite a distinct species, 

 and belongs to the genus Omalovyx, as shown by Hejnemann's 

 figure of the jaw (MaL Blatt., xv.). 



I give also figures of the central and lateral teeth of our species 

 (pi. VIII., fig. 6). 

 Amphibulima patula, Brug. 



I have elsewhere described, in connection with Mi*. Bland, the 

 jaw and lingual membrane of specimens of this species from St. Kitts 

 and Dominica (Am. Journ. of Conch., YII. 186, pi. xvii., f. 1, 2; 

 Ann. Lye. N. H. and N. Y., x. 225, pi. xi., f. 8). Lately the question 

 of identity of these shells with tlie Guadeloupe |>a<uZa has been 

 raised (see Journal de Conch3'liologie, XXI. 12). I have, therefore, 

 again carefully examined the lingual membranes previously de- 

 scribed to learn if they give au}^ difference worthy to be considered 

 of specific value. 1 have figured teeth from each lingual mem- 

 brane (i)l. VII.). I regret not having had the opportunity of exam- 

 ining Guadeloupe specimens also, but have never heen able to 

 receive the latter witli the animal ; indeed it seems to be now 

 found subfossil only. I can only treat the question of the identity 

 of the St. Kitts and Dominica forms, not their identit^'^ with Guade- 

 loupe forms. 



It will be seen that the Dominica form has sharper cutting 

 points to the large cusps of its central and lateral teeth than that 

 of St. Kitts. Fig. B shows a group of laterals of the former, in 

 which some variation from the pointed shape is indeed shown, but 

 no decided tendency that way. On the other hand, the laterals, 

 from the St. Kitts form, show great constancy in the square trun- 

 cation of the cutting points. 



The teeth of the St. Kitts form are broader in proportion to 

 their length than those of Dominica, have a greater curve in their 

 outlines, and more developed side cusps, which overlap the me- 

 dian cusps. 



The Dominica lingual in the only row counted had 87-1-8Y 

 teeth. A row of the St. Kitts form 51-1-57. The marginal teeth 

 of the St. Kitts form show a greater tendenc}' to splitting into 

 sharp denticles on the cutting cusps than those of Dominica. 



It cannot be denied that certain variations may be noticed in 

 the two lingual membranes. 1 believe, however, that tliese differ- 



