112 Dentition of Pulmonale Mollusks. 



rounded • a decided median projection to the cutting edge, marked with 

 strong vertical striae. • 

 Lingual membrane as in other species. (PI. IX, fig. I.) 



Dentellaria perplexa, Fer. Island of Grenada. Gov. Rawson. 



Jaw with a median projection to its cutting edge, The anterior surface 

 js of irregular thickness, showing some approach to the ribbed form of jaw. 

 (PI. XVI, fig. T.) 



Lingual membrane as usual. Central and lateral teeth with short, stout, 

 blunt cusps.' Marginal teeth quadrate, with one wide, stout, bluntly rounded 

 median cusp, and two small, blunt side cusps. (PL IX, fig. J.) 



Dentellaria lyolinuclius, Mull. Guadeloupe. Mr. A. Schramm. 



Jaw (PL XVI, fig. U) arched, ends blunt, cutting margin with a broad, 

 blunt, median projection; strong vertical stria; and transverse lines of re- 

 inforcement, and subobsolete ribs, which denticulate the upper margin. 



Lingual membrane as in the other species. (PL IX, fig. K.) 



Pleurodonta. 



The jaw is decidedly costate. Lingual membrane much as in 

 Plagioptyclia and Dentellaria. 



Pleurodonta acuta, Lam. Jamaica. 



Jaw arched, thick, ends blunt, attenuated; anterior surface with seven 

 distant, stout ribs, denticulating either margin. 



Lingual membrane (PL X, fig. A) with 40-1-40 teeth as above; the mar- 

 ginal figured has only one long, oblique cutting point. 



Pleurodonta Chemnitziana, Pfr. Jamaica. Mr. Robert Swift. 

 Jaw stout, arched, ends attenuated, blunt ; anterior surface with about 

 six irregularly disposed ribs, stout and denticulating either margin. 

 No lingual membrane received. 



Pleurodonta Carmelitd, Fer. Jamaica. Mr. Robert Swift. 



Jaw arcuate, ends blunt, anterior surface with about six stout ribs, den- 

 ticulating either margin. 



Lingual membrane (PL X, fig. B) as usual in the genus. Central teeth 

 short, bluntly pointed on the middle cusps, the side cusps subobsolete ; lat- 

 erals like centrals, also with obsolete side cusps and cutting points; mar- 

 ginals low, wide, with an inner large, oblique, bluntly trifid cutting point. 



Pleurodonta Schroeteriana, Pfr. Jamaica. Mr. Vendreyes. 



Jaw not examined. 



Lingual membrane (PL X, fig. C) as in other species. 



Pleurodonta invalida, Ad. Jamaica. Mr. Henry Vendreyes. 

 Jaw not examined. 



Lingual membrane (PL X, fig. D) as in the other species. Centrals and 

 laterals short and stout. 



