100 THE NAUTILUS. 



suture to the superior angle, which is quite obtuse, periphery cari- 

 nate, the whorl being almost straight between the two angles, 

 obliquely flattened below. Aperture moderate, subcircular; slightly 

 modified by the angle of the body-whorl, and slightly expanded at its 

 juncture with the columella. Columella very narrow, rounded; 

 columellar callus not very heavy, thin and transparent on the 

 parietal wall. 



Alt. 3, diam. 2.75 mm. 



Tennessee River, Florence, Ala. Types (No. 22376 Coll. Walker). 

 Cotypes in collection of A. A. Hinkley. 



Only two specimens of this remarkable little species were found. 

 But it is so entirely distinct from all the known species that I have 

 no hesitation in describing it. With the exception of S. aldrichi, 

 herein described, it is the only carinate species known. 



SOMATOGYRUS EXCAVATUS, 11. Sp. PL 5, fig. 7. 



Shell small, globosely-conic, imperforate, rather thick, solid, pale 

 green, smooth, lines of growth very fine. Spire short, conic, obtuse ; 

 whorls 3^; those of the spire convex, with a well-impressed suture; 

 body-whorl rather inflated, convexly rounded. Aperture subcircular, 

 slightly angled above and broadly rounded below. Columella very 

 concave, with a moderately wide, heavy, flat callus, which extends 

 over the parietal wall, and below the axis is separated by a wide 

 axial groove. Lip simple, but thickened within and somewhat 

 emarginate below. 



Alt. 3|, diam. 3 mm. 



Shoal Creek, Florence, Ala. Types (No. 22378 Coll. Walker). 

 Cotypes in the collections of the Academy of Natural Sciences and 

 A. A. Hinkley. A solid little species, distinguished by its globosely 

 conic shape, thickened lip and axial groove. 

 (To be continued.) 



A NEW TERTIAEY PLANORBIS. 



BY T. D. A. COCKEKELL. 



Planorbis florissantensis, n. sp. 



Diameter about 2| mm., flattish, with about 4£ slightly convex 

 whorls, the last rapidly enlarging, much in the manner of P. albus, 



