Foreign to the United Slates. 221 



prove the genus Leucochroa to be only a subgenus of Helix, 

 in the iirrangemeut of "Die Ilclicecn." 



Melix ©ircaiBM]faB"sassstsa, Redfiixp. 



Lingual membrane long and broad, centrals tricuspid, laterals bicuspid, 

 cusps long and slender, marginals aculeate. 



From the above description it will appear that this spe- 

 cies belongs to the Vitrinea rnther than to (he Helicea of 

 von Marten's arrangement, in which hitter it is chissed in 

 "Die lleliceen"as a species of the subgenus jMicrojj/tym. 



Jaw extremely thin, arched, witii a blunt, median projection to its 

 cutting edge. 



Lingual membrane long and narrow. Central teeth tricuspid, laterals 

 bicuspid; tlie cusps in each long and slender. Marginals numerous, 

 aculeate in oblique rows. * 



As in the 11. circumfirmata , the result of our examina- 

 tion of the lingual membrane throws light on the generic 

 position of this species. It can no longer be retained in 

 Caracohts, a sub-genus of Helix, as it has the dentition of 

 the Viirinea of von Marten's arrangement. For the speci- 

 mens examined of this and the preceding species, botli from 

 Bermuda, we are indebted to Mr. J. J. Crooke. 



ISeMx p4?rg>Se2;a, Fer. {Dcntdlaria). 



.Jaw with a median projection to its cutting edge. The anterior sur- 

 face of the jaw is of irregular thickness, showing some approach to the 

 ribbed form of jaw. 



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. 



We are indebted to Governor Rawson for this specimen 

 collected in the Island of Grenada. 



