172 Two New Species of North American Ilelicidai. 



distinctly reflected, and thickened within, basal margin slightly 

 arcuate, but entire. 



Diam. maj. 10 mill. Diam. min. 9 mill. Alt. 6 mill. 



Habitat. — Habersham Co., Georgia, where it was collected 

 by Bishop Elliott. 



Observations. — Closely allied to II. spinosa Lea, and H. 

 Edgariana Lea ; but a careful examination of many indivi- 

 duals of the three types led me to concur in the conclusions 

 previously arrived at by Mr. Bland and Mr. Binney, that the 

 three forms are specifically distinct. In size the H. barbigera 

 resembles II. Edgariana, but is readily distinguished by its 

 much more slender parietal tooth, and by the absence of the 

 notch in the peristome. The notch is usually present also in II. 

 spinosa, but that species, like II. Edgariana, has the parietal 

 tooth elongated and very strongly developed. Moreover, II. 

 barbigera is much smaller than II. spinosa (being only about 

 two-thirds its diameter), and has about half a whorl less. 

 The epidermidal strice are more numerous, more sharply raised, 

 and as a consequence the cilia are more numerous than in 

 II. spinosa. In the latter the lower lip rises from a deep 

 excavation in the umbilical region, and the parietal tooth 

 is partially curved round the excavation, somewhat over- 

 lapping the lower lip at its junction with the columella. This 

 peculiarity is most distinct in the large form of II. spinosa from 

 Alabama, less so in the smaller form from Tennessee. In II. 

 barbigera the base is less excavated, and the lower lip does not 

 descend into it, and is not overlapped by the parietal tooth, 

 indeed the general character of the lower lip and tooth are 

 more allied to H.fraterna Say than to II. spinosa. The lip 

 is distinctly reflected, not merely appressed, as in II. spinosa. 



The three forms, II. barbigera, II. sp)inosa, and II. Edgar- 

 iana bear to each other relations somewhat analogous to those 

 which connect II. fratema Say, II. hirsuta Say, and II. 

 niaxillata Gould. 



