176 Binney on Terrestrial Molhisks. 



DESCRIPTION. 



Animal not observed. 



Shell sinistral, ovate-lanceolate, acuminate, pellucid, 

 highly polished and glistening. Whorls seven, very ob- 

 lique, scarcely convex, the last one somewhat ventricose 

 towards the base, about two thirds the length of the shell. 

 Aperture narrow ovate, acutely prolonged posteriorly ; lip 

 simple ; turning up the columella it becomes thickened, 

 and winds into the aperture in the form of a tooth-like 

 lamella. 



Length one tenth of an inch ; breadth one thirtieth of 

 an inch. 



Geographical Distribution. Found in Florida, among 

 small shells drifted in the sand. 



Dr. Foreman collected a few specimens in a garden of 

 Washington city. He believes them to have been brought 

 on plants from Charleston, S. C. 



It has been detected in Cuba, Jamaica, and Porto Rico, 

 and has been introduced into England. 



Remarks. Perhaps no shell has rejoiced in more 

 numerous and longer names, both generic and specific, 

 than this minute one. Nor has the true station of any 

 one been more ditlicult to decide. It is now, however, 

 acknowledged to be air-breathing, and amphibious in its 

 habits. 



Binney is the only American author who mentions its 

 existence in this country. He places it under Achatina. 

 Gould, in Terr. Moll., leaves it in that genus provisionally, 

 mentioning the doubt existing concerning it. 



Shuttleworth in letters to Bland adds to the synonymy. 



Voliilft lieti'roclitd Mo.M'., Laskicy. 

 Aclwon hettruititu Flkming. 

 Aitrkula helerodila Thoiu'K. 



Tornalella? helerodila Fuubes & Hani.ky. 



