30 Hemarhs on Certain Species of 



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



" Desk, 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 snbtiliter 

 striata, cornea, diaphana, imperforate, anfr. 5 ; apertura snbrotundata ; 

 labro reflexo ; columella Isevi. 



" Shell above obtusely conical, below inflated, longitudinally and 

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

 nearly round ; outer lip reflexed ; columella smooth. 



^'■Remarks: I am indebted to ]>. Mitchell for this shell, which was 

 sent to him by a friend from Ohio. It is rather larger than the H. 

 clausa Say, and H. jejuna Say, but in form resembles them. It may be 

 distinguished from the latter in not being perforate, and from the former 

 in having a sharper lip. In its striae it is distinct frona both, in having 

 them larger and much better defined. 



" Hab. Ohio. Diam. 7. Length .4 of an inch." 



Lea's description agrees fairly with the shell now known in 

 our cabinets as H. Mitchelliana. 



Looking at his " Remarks," however, I cannot wonder at the 

 many doubts which have arisen as to the shell intended to be 

 indicated, inasmuch as the comparison with H. clausa and II. 

 jejuna scarcely admits of satisfactory explanation. 



The fact is, that Lea misapprehended both species, as I learn 

 from correspondence with him, — he had in his cabinet under the 

 latter name, a small form of H. clausa^ and I have reason to 

 believe that a variety, with imperfectly developed lip, of the 

 very shell which he was about to describe as H. Mitch- 

 elliana, represented the former species. The language used 

 by Lea shows that he referred to an irrvperforate shell as II. 

 clausa. 



H. Mitchelliana is certainly very closely allied to H. clausa, 

 especially the form described by Say, but in Lea's species the 



