98 Descriptions of New Fluviatile Shells. 



others, and the folds are arrested by it near the suture. The 

 penultimate whorl is often sub-angulated at its base. 



16. llclania baculuiii. 



Plate II. Fig. 10. 



T. elongato-conica, crassa, fulvo-castanea ; spira perelevata, decollata ; 

 anfr. superst. 8, subplanis, plicis transversis stiiisque spiralibus decussatis, 

 quae in anfr. inferioribus obsolescunt; suturis impressis, flavescentibus ; 

 apertura ovata, intus purpurascente ; columella incurva, foveata, in sinum 

 tenue.m products. 



Shell conical, thick; of a dull, reddish-brown color, with a 

 lighter shade near the upper part of each whorl. Spire much 

 elevated, not diminishing rapidly as it ascends, and with nearly 

 a rectilinear outline ; whorls 8 remaining, and with an appear- 

 ance of having lost several by truncation ; hardly convex and 

 with a deeply impressed suture ; aperture small, broadly ovate, 

 light red within ; columella rounded, indented, with a small 

 sinus. 



Length 1.28 inch (33 millim.). Diam. 0.48 inch (12 millim.). 



Length of aperture 0.35 inch (9 millim.). 



Breadth of do. 0.20 inch (5 millim.). 



Habitat. — Tennessee. 



My cab. Cab. Lye. Nat. Hist., N. Y. B. W. Budd, M.D. 



Obs. — The most striking characteristic of this species is its 

 robust cylindrical form, combined with its. pale sutural region; 

 compared with M. teres Lea, it is much less slender and turret- 

 ed, much more plicate, and the whorls are less inflated. M. 

 rufa is not folded, and is a more acutely elevated species. The 

 curve in the columella resembles that of M. columella Lea, but 

 that shell is much less elongated, has only six whorls, and is 

 destitute of distinct folds. 



