48 Binney on Terrestrial Mollusks. 



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

 aperture neai'ly round ; outer lip reflexed ; columella smooth. 



Remarks. I am indebted to Dr. Mitchell for this shell, which 

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

 the H. claiisa 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 

 from both, in having them larger and much better defined. 



Hah. Ohio. Diam. 7. Length .4 of an inch. [Lea]. 



SYNONYMS AND RKFERENCES. 



Helix Mitclielliana Lka, 1. c. 



Troschel, Ar. f. Nat. 1839, ii. 221. 



DeKay, N. Y. Moll. p. 45. 



Pfeiffer, Mon. Hel. V. i. 291 ; iii. 270. 



Bland, N. Y. Lyceum, vi. 339 ; Notes 29. 

 Helix clausa Binney, ex parte, p. 109. 



In addition to the above synonymy, Pfeiffer and Bland 

 quote doubtfully DeKay's figure of clausa. It is certainly 

 little characteristic of either MitcheUiana or clausa. 



Lea's figure is poor, and his remarks had better be en- 

 tirely cancelled, having been written under a misappre- 

 hension of both the species referred to. 



The figures I have referred to were intended to represent 

 this species, and appear to me to do so. My friend Mr. 

 Bland, however, refers them to clausa. 



The shell figured by Deshayes under this name is H. 

 Pennsylvanica. The figure in Chemnitz represents H. 

 clausa. Anthony (Ohio Cat.) places MitcheUiana in the 

 synonymy of clausa, and Kirtland (Ohio Rep.) seems to 

 have catalogued it under the name of Mitchella. 



I have never known this species to be found out of 

 Ohio, where it appears to be not uncommon. It is 

 readily distinguished from clausa by its more globose 

 form and smooth, shining surface, its imperforate base, 

 and by the following peculiarities pointed out by Bland. 

 (1. c.) 



