Wi 



^^ JRemarTcs on GeHain Species of 



F^IV- H. auriculata^ and the rib-like striae, M'hieli cover the 

 wiiole of that shell, are scarcel}^ developed at the 

 base. The form of the parietal process is very 



JI. postelliana , , ,» tt- t • /« i i 



Bland. like that 01 H. uvuL-ijera, but the continuation 

 of its inferior angle to the inner termination of the labrum 

 is not prostrate as in that species, but erect as in H. aui'i- 

 culata. The position and form of the upper tooth on the 

 labrum is much the same as in that species, and in H. uvullfera^ 

 but tbe lower one is entirely different. In those it is an oblique, 

 strongly developed, convex, sinuous fold on the margin of the 

 labrum, not descending into the aperture, there being within 

 a slight thickening only, corresponding with the lower exterior 

 apertural depression. 



In //. PosteUiana there is at the base of the labrum a thin, 

 erect, oblong, lamelliform tooth, rather oblique, but more 

 closely marginal than the fold in the other species. The exterior 

 of this tooth is convex, within concave, it is 1 mill, in height, 

 and 1^ in length, and descends rapidly into the aperture, where 

 it is recurved, and terminates obtusely opposite to the lower 

 end of the superior tooth, there being a vox^ distinct and tor- 

 tuous sinus between the two. I have opened specimens from 

 different localities, and find these characters constant. 



This is, I believe, the shell which Dr. Binney supposed to be 

 the II. avara Say — specimens from his cabinet, as well as one 

 sent to me by the late Judge Tappan, all so labelled, induce this 

 opinion. The small figures, however, in the Boston Journal, 

 and Terr. Moll, scarcely represent this form. 



I name this species after raj^ liberal correspondent Mr. James 

 Postell, in acknowledgment of the valuable assistance which I 

 have received from him, in my endeavor to elucidate the 

 l^orth American Helices. 



Mciix atiFirorsMis ISBnssd. 



Iloiix aurkulata Binney^ Bost. Jl. (ex parte), pi. xix. fig. 2, 1S40 

 " " Desk, in For. Hist. var. minor, pi. 50, fig. 3. 



