44 PROCEEDINGS OF THE ACADEMY OF 



we find in onr S. appendiculata. His species and ours are there- 

 fore distinct. 



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

 and belongs to tlie genus Omalonyx^ as sliown by Heynemann's 

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



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

 (pl.YIII.,fig. 6^). 



Amphibulima patula, Brug. 



I have elsewhere described, in connection with Mr. Bland, the 

 jaw and lingualmembraneof 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 the Guadeloupe jja/^Jo has been 

 raised (see Journal de Conch^liologie, XXL 12). I have, therefore, 

 again carefull}' examined the lingual membranes previously de- 

 scribed to learn if the}- give any difference worthy to be considered 

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

 brane (pi. YIL). I regret not having had the opportunity of exam- 

 ining Guadeloupe specimens also, but have never been able to 

 receive the latter with 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 tendenc}' 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 onl}'^ row counted had 81-1-87 

 teeth. A row of the St. Kitts form 57-1 -5T. The marginal teeth 

 of the St. Kitts form show a greater tendency to splitting into 

 sharp denticles on the cutting cusps than tliose of Dominica. 



It cannot be denied that certain variations may be noticed in 

 the two lingual membranes. I believe, however, that these differ- 



