Descriptions of New Fluviatile Shells. 



Habitat. Mammoth Cave, Kentucky. 

 My cabinet. 



Obs. Bears no very strong resemblance to any known 

 species ; but is perhaps more nearly allied to M. rufa Lea and 

 M. teres Lea in its elevated spire and convex whorls. It wants, 

 however, the smooth whorls of the former, its dark red color, 

 and elliptical aperture. From the latter it may be distinguished 

 by its striated whorls, its less slender proportions, the absence 

 of folds, its obscure bands, and white aperture. This species is 

 unusually interesting, from the fact that it is the first species in 

 Conchology known to have been procured from the subterra- 

 nean river flowing through the Mammoth Cave. 



1. ITIelaiiia yittata. 



Plate II. Fig. 7. 



T. conica, subglabra, fusco-vi rente; spira elevata ; anfr. 9, planis, 

 lineis duabus fuscis ornatis, quarurn inferior in angulum prope suturam 

 revolvit, lineis in anfr. suprerais obsoletis, in ultimo 4 vel 5 conspicuis ; 

 suturis valde impressis ; apertura ovata, intus albida, fusco quadriline- 

 ata; columella incurva, in sinum tenuem producta. 



Shell conic, nearly smooth ; spire elevated ; whorls about 9, 

 flat, with two fine, distant, brown lines on each, the lower one 

 revolving upon an angle near the suture ; lines obsolete on the 

 extreme upper whorls, and increased to four or five on the body 

 whorl, visible also within the aperture; sutures deeply im- 

 pressed; aperture ovate, within whitish, but exhibiting also 

 the brown lines of the epidermis ; columella curved, sinus incon- 

 spicuous. 



Length 0.86 inch (22 millim.). Diam. 0.32 inch (8 millim.). 



Length of aperture 0.33 inch (8 millim.). 



Breadth of do. 0.16 inch (4 millim.). 



