NATURAL SCIENCES OF PHILADELPHIA. 135 



NOTES ON LINGUAL DENTITION OF CERTAIN SPECIES OF NORTH 

 AMERICAN LAND SHELLS- 



BY THOMAS BLAND AND W. G. BINNEY. 



"We are indebted to Miss Annie E. Law, of Jalapa, Tennessee, 

 and to Mr. Henry Hemphill, of Oakland, California, for the 

 specimens from which we extracted the jaws and lingual mem- 

 branes here described. 



ZONITES LJ3VIGATUS, Pf. 



Jaw as usual in the genus. 



Zonites intertextus, Binney. 



The jaw and lingual membrane are as usual in the genus. 



Zonites demissus, Binney. 



Jaw arched, ends attenuated, pointed; anterior surface smooth, 

 cutting edge with well developed sharp median projection. 



Lingual membrane as usual in the genus. Laterals above 

 eight in number on either side of central line. 



Zonites lasmodon, Phillips. 



Jaw and lingual membrane as usual in the genus. 

 Zonites inteknus, Say. 



The jaw and lingual membrane are those of Zonites (or Hya- 

 lina), and not of Helix, tlius showing the generic position of the 

 species, which is not so well marked by the shell. 



The jaw is slightly arcuate, ends attenuated, pointed ; median 

 beak-like prominence to the cutting edge. 



The lingual membrane is long and narrow. Central teeth 

 large, with a long median cusp. Laterals like the centrals, but 

 bifid, four in number, marginals aculeate. 



Patula strigosa, Gould. 



Jaw long, low, slightly arcuate ; anterior surface smooth except- 

 ing near the lower margin, where there are numerous, crowded, 

 subobsolete ribs, or coarse strise, crenellating the cutting edge. 

 There is a very strong muscular attachment to the upper margin. 



The lingual membrane is as usual in the genus. (See fig. 129 of 

 L. and Fr. W. Shells, I.) The marginal teeth are wide and low, 

 with one inner, long, obtuse, oblique denticle, and several short 

 side blunt denticles, obtusely rounded. 



