206 On the Relations of Certain 



SiLccinea aj)j)endtculata, identical with S. depressa Rans:, 

 is miide by Fischer the type of a separate genus, Pellicula, 

 after an examination of the jaw, lingual dentition and gen- 

 erative organs; Albers {I. c.) adds that he had not yet 

 been able to decide upon the correctness of those views. 



From the subjoined diagnosis of the species received as 

 Succlnea append Iculata iwnw Guadeloupe, it will be seen that 

 the animal is limaciform, has a jaw, not as in 0. unguis, but 

 allied to that of genera and species of Ilellclnm, and teeth 

 agreeing somewhat closely with those of Slmpulopsls. In 

 pi. ix, we give figures of the animal (from an alcoholic spec- 

 imen), of part of the jaw and teeth (Figs. 2, 9, 10, 11). 



We now proceed to describe the jaw and lingual membrane 

 of Succlnea appendiculata Pfr., received from Governor 

 Raws on : 



Jaw extremely tliin and transparent, long, low, slightly arcuate, ends 

 blunt, divided longitudinally by about 40 delicate ribs into as many 

 plate-like sections, of the character found in the jaws of Cijlindrella, 

 3Iacroceramus and many species of Bulimulus. No appearance of trian- 

 gular upper median plates, however, as in Gylindrdla, though the two 

 specimens examined by us are not perfect at that part. Both margins 

 serrated by the extremities of tiie ribs. The general character of these 

 I'ibs is the same as in Helix turbini/urmis, figured by us in Ann. of Lye. 

 of Nat. Hist. N. Y. x, pi. 2, flg. 2. The jaw is quite membranous. 



Lingual membrane as usual in the Ilelicince proper (see Ann. Lye. Nat. 

 Hist. N. Y. X, 163).. Centrals subquadrate^with a very large, stout, short, 

 pointed cusp, the side cusps obsolete. Laterals larger and more narrow 

 than the centrals, bicuspid, the inner cusp greatl^'^ produced, broad 

 and quite squarel}' terminating. The base of attachment of the laterals 

 is cut away on the inner side, leaving a large outer lateral expansion, 

 bringing to mind the much less developed one of Succinea. Marginal 

 teeth quadrate, gradually becoming moditied from the laterals, the cusps 

 finally passing off into simple, obtuse papillas, the inner one the larger. 



The central and lateral teeth are lilce those of Siinpiilopsis sulculosa as 

 tigured by Heynemanu in Malak. Blatt. xv, pi. 5, (ig. 10, the central, 

 however, bearing a much more developed cusp in our species. The 

 marginals in that figure, of the form found in Bulimulus aurisJeporis, 

 papyraceus, laticinctus, etc., we failed to detect in our species. As already 

 stated, we found the marginals merely a modification of the laterals. 



The above description does not agree with that given by 

 Dr. Fischer (Melanges Conch., GO, t. vi, tig. Id) oi Pellicula 



