Genera of Terrestrial MoUusca, etc. 207 



depressa, which we have already quoted. He describes the 

 jaw as having a number of ribs on its anterior surface pecti- 

 natingthe cutting margin, actually nine of them being shown 

 in his figure. He also describes the lingual dentition as 

 quite different, the centrals being represented with one large 

 bifid median cusp and one small cusp at either side. His 

 figure of the lateral teeth is also simply bicuspid, the figure 

 of the inner cusp does not show any trace of the peculiar 

 prolongation and blunt termination, described by us above. 

 For convenient reference we copy Fischer's figure of the 

 jaw (Plate ix, fig. 4). 



The external appearance of our animal is the same as 

 described by Fischer in the paper referred to. Little confi- 

 dence, however, can be placed on the external characters of 

 the animals of this group, that of O. unguis being, as 

 Fischer remarks, nearly the same as of the species under 

 consideration. 



As already mentioned, P. convexa v. Mart., from its form 

 of jaw, cannot be placed in Fischer's genus Pellicula, while 

 the appendiculata examined by us has jaw (as well as teeth) 

 of difierent character from that assigned by Fischer to Pellicula 

 depressa, but for the present we refer, with doubt, our spe- 

 cies to Pellicula; most certainly it does not belong to 8uc- 

 cinea. 



We appear to be warranted in assuming that Mr. Rawson's 

 appendiculata is Pfeiflfer's species, specifically and probably 

 generically distinct from S. depressa Fischer. Whether the 

 latter is or is not the S. depressa Rang we are unable to 

 decide. 

 Dec£mb£b, 1872. 15 Ann. Ltc. Nat. Hist., Vol. x 



