Foreign io the United States. 221 



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

 in the arrangement of "Die Heliceeii." 



Helix circianafii'iuata^, Redfield. 



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 rather than to the Helicea of 

 von Marten's arrangement, in which latter it is classed in 

 *'Die Heliceen" as a species of the subgenus Micvojpliysa. 



!15ell3c: lIea'iM«a^ei2®i§, Per. 



Jnw extremely thin, arched, with a blunt, median projection to its 

 cutting edge. 



Lingual membrane long and narrov/. Central teeth tricuspid, laterals 

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

 aculeate in oblique rows. 



As in the II. 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 

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

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

 mens examined of this and the preceding species, both from 

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



ISelix perplexsa, Fer. {Bentellaria). 



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 Eaw^son for this specimen 

 collected in the Island of Grenada. 



