Descriptions of New Fluviatik Shells. 

 26. Helania pagodiformis. 



Plate III. Fig. 6. 



T. conica, tenui, fusca ; spira obtuse elevata ; anfr. 7-8, carina ele- 

 vata, acuta, supra suturam cinctis, ultimo carinis duabus instructo ; sutu- 

 ris valde impressis ; apertura ovata, infra subangulata, intus albida ; 

 columella incurva, in sinum tenuem angustura producta. 



Shell conical, thin, brownish-olive ; spire obtusely elevated ; 

 whorls 7-8, smooth ; the upper ones are surrounded by a sharp 

 elevated keel just above tfre suture ; the body whorl is angu- 

 lated in the middle by two keels, of which the upper is the 

 more prominent; sutures deeply impressed; aperture ovate, 

 ending in an acute angle below, whitish within ; columella 

 rounded, produced into a narrow but slight sinus. 



Length 0.50 inch (13 millim.). Diam. 0.28 inch (7 millim.). 



Length of aperture 0.26 inch (7 millim.). 



Breadth of do. 0.14 inch (3J- millim.). 



Habitat. Battle creek, Tennessee. 

 My cab. Cab. Lye. Nat. Hist., N. Y. 



Obs. Bears some resemblance to M. acuto-carinata Lea, but 

 differs from it in many particulars. It is of a much lighter 

 color, has the carina on every whorl, the body whorl not ex- 

 cepted, its columella is not remarkably indented as in that 

 species, and it is altogether a thinner and broader shell. The 

 aperture is generally uncolored, but some specimens present a 

 faint tinge of violet there. 



27. jflelaiiia exiiiiia. 



Plate III. Fig. 7. 

 Testa conico-ovata, lirata, corneo-virente ; spira parum elevata ; anfr. 



