110 THE NAUTILUS. 



dentata and lamellidens in the same general locality, although he did 

 not find the latter in Alabama. 



The species is so distinct from all others of the genus that it can 

 not be compared with any of them. The fact of finding four speci- 

 mens at different places and all of practically the same size, shows 

 that it is not likely to be the young of a larger species. 



I take great pleasure in naming it after Hon. T. H. Aldrich so 

 well-known by his work on the fossil mollusca of the South. 



Type in my collection ; the other specimens in the collections of 

 Bryant Walker, John B. Henderson, Jr., and T. H. Aldrich. 



Polygyra (Stenotrema) brevipila n. sp. PI. V, figs. 1, 2, 3, 4. 



Shell imperforate, globose, thin, light reddish-horn color ; densely 

 hirsute with fine, short hairs. Whorls five, those of the spire convex 

 with a well-impressed suture ; the body-whorl very convex, equally 

 rounded above and below, deeply impressed in the umbilical region, 

 abruptly deflected at the aperture and contracted behind the lip. 

 Aperture transverse, narrow, widening anteriorly; parietal tooth 

 large, strong but narrow, erect, with the sides nearly at right angles 

 to the whorl and projecting beyond the lip, with which it is not 

 parallel, but diverges for three-fonrths of its length, when it is abruptly 

 bent inward and downward, terminating opposite the second notch 

 in the lip, its distal or outer extremity connected with the end of the 

 peristome by a ridge of callus, the axial end sweeping around and 

 "pocketing " the basal end of the lip ; outer lip reflected back against 

 tha body-whorl, but with its sharp edge free from the tvhorl its entire 

 length; very much thickened along its inner edge which forms a 

 raised margin around the wide notch, and a well-developed tooth or 

 fold beyond it, after which the margin is incurved around the outer 

 extremity of the parietal tooth. Fulcrum long. 



An average shell measures, diam. 8^, alt. 6 mm. 



The largest seen measures 9x6, and the smallest 7f x 5 J mm. 



Collected by Herbert H. Smith on Horseblock Mountain, Talla- 

 dega Co., Ala., at an altitude of about 2,000 feet. On some of the 

 U. S. Geological Survey sheets this mountain is called " Talladega," 

 but " Horseblock " is the local name. 



" The mountain sides, near the top, are littered, or rather piled 

 with talus, big and little rocks ; the shells are found almost invari- 

 ably on the lower sides of these rocks, and generally they chose 



