Descriptions of New Fluviatik Shells. 

 18. Melania excavata. 



Plate II. Fig. 18. 



T. ovato-conica, glabra, crassa, castanea ; spira obtuse elevata, decol- 

 lata ; anfr. superst. 3-4, planis vel subconcavis, ultimo in medio suban- 

 gulato, supra angulum subexcavato, striis incrementi rudibus ; suturis 

 distinctis; apertura ovata, sursum subcanaliculata, intus rubescente; 

 columella incurva, reflexa, sinum non formante. 



Shell ovate-conic, smooth, olivaceous, thick; spire obtusely 

 elevated, decollate ; whorls 3-4, remaining flat or concave ; 

 sutures distinct ; penultimate and body whorl with a broad, 

 deep, concave excavation, their edges being elevated into an 

 obtuse carina, tipped with a lighter color ; lines of growth very 

 strong; aperture not large, ovate, reddish within; columella 

 regularly curved, thickened by a deposit of calcareous matter, 

 purplish and white, indented near its base, without any sinus. 



Length (of an eroded example) 0.84 inch (21 millim.). 



Diam. ( do. do. ) 0.44 inch (11 millim.). 



Length of aperture 0.40 inch (10 millim.). 



Breadth of do. 0.22 inch (5J millim.). 



Habitat. Alabama. 

 My cabinet. 



. An unadorned species of a dull olive color, not easily 

 confounded with any of its congeners. Differs from M. fusi- 

 formis Lea by its broad, more elevated spire, its purple mouth, 

 unadorned with bands, but above all, by the peculiar excava- 

 tion on the lower whorls, which is so peculiar as to distinguish 

 this species from all others. 



19. Ulelaiiia casta. 



Plate II. Fig. 19. 

 T. conica, plerumque glabra, crassa ; spira obtuse elevata ; anfr. 6-7, 



