North American Helicidce. 339 



ma variety, and alluded, when writing of the covered umbilicus, 

 to II. Mitchelliana Lea, which he puts in the synonymy of 

 H. clausa. 



.Mr. W. G. Binney, in his " Notes on American Land Shells " 

 (Phil. Proc. 1857), states that the outline figures in Terr. Moll. 

 (PI. 4) do not represent II. clausa ; they are, however, very 

 like my small Alabama or Tennessee specimens. 



De Kay describes U. clausa as having the umbilicus occa- 

 sionally entirely covered ; and states, erroneously, that it may 

 be considered as a Southern species, extending to New Jersey 

 and New York. 



Reeve's figure of H. clausa (fig. 676), I have already referred 

 to as being H. Pennsylvania. He gives another (fig. 694), 

 which may be the var. subalbolabris, but is more like II. buccu- 

 lenta Gould, without the parietal tooth. 



Helix Mitchelliana Lea. 



Synonymy. 



Helix Mitchelliana Lea Am. Phil. Trans. VI. 87, pi. 23, f. 71, 1836. 



clausa De Kay N. Y. Moll. p. 31, ex parte, pi. 2, f. 13 ? 1843. 



Mitchelliana Pfr. Mon. I., No. 760, 1848. 



u Desh. in Fer. Hist, ex parte ? excl. fig. 



clausa Binney Terr. Moll. p. 107, ex parte, 1851. 



The following is Mr. Lea's description : — 



" H. Mitchelliana. 



" T. superne obtuso-conica, inferne inflata, longitudinaliter et subtiliter 

 striata, cornea, diaphana, iraperforata, anfr. 5 ; apertura subrotundata, ; 

 labro reflexo ; columella laevi. 



" Shell above obtusely conical, below inflated, longitudinally and 

 finely striate ; horn color, transparent, imperforate ; whorls 5 ; aperture 

 nearly round ; outer lip reflexed ; columella smooth. 



