100 Dentition of Pubnonate Mollusks. 



The figures of the jaw and lingual dentition of this species were photo- 

 graphed from the microscope by my friend, Mr. Samuel Powel, of Newport, 

 to whom I am greatly indebted for assistance in my studies of lingual den- 

 tition. 



Stenogyra. 



See Terr. Moll., V, for dentition of 8. subula, Pfr. . and 

 decollata, Lin. 



Stenogyra gonostoma. Gundl. Cuba. I). Rafael A'rango. 

 Lingual membrane as in next species. 



Stenogyra octona, Chemn. Bahia. J. G. Anthony. 



Lingual membrane short and broad. 



Teeth about 30-1-30. Centrals with base of attachment long, narrow, an- 

 gularly expanded at centre ; reflection small, bluntly tricuspid, the central 

 cusp bearing a short, stout, cutting point ; laterals much larger, as wide as 

 long; reflection very large, with an inner median large, and a small outer 

 cusp on each side of it, all the cusps bearing distinct cutting points ; mar- 

 ginal teeth low, wide, irregularly denticulated by minute cutting points. 

 The peculiarity of the dentition, as in the other species of Stenogyra, is the 

 small central as well as distinctly tricuspid laterals ; the latter are not 

 crowded on the membrane. 



Stenogyra liasta, Pfr. Cuba. 



Jaw (PI. XY, fig. I) low, arcuate, ends somewhat attenuated, blunt; no 

 median projection to cutting margin; anterior surface with numerous, ver- 

 tical, delicate, striae. 



Lingual membrane (PI. YII, fig. D). Teeth 18-1-18, as usual in the genus. 

 (See Terr. Moll., V.) 



Stenogyra juncea, Gld. Island of Huahine. Mr. A. Garrett. 

 Described by Gould and PfeifEer as a Bulimus. 



Lingual membrane with 28-1-28 teeth, eight of which on each side are 

 laterals ; dentition as in S. hasta . 



Strophia. 



See Terr. Moll., V, for jaw and lingual dentition of S. incana. 

 Strophia decumana. Fer. Castle Island, Bahamas. 



Jaw stout, strongly arcuate, ends slightly attenuated, bluntly rounded; 

 anterior surface ribless, transversely striate, and with several stout lines of 

 reinforcement; a small, blunt, median projection to the cutting edge. 



Lingual membrane (PI. YII, fig. A) with 30 1-30 teeth; centrals short, 

 about as broad as long, with short, stout median cusps to the reflection, 

 bearing a stout, broad cutting point, and subobsolete side cusps bearing 



