Descriptions of New Fluviatile Shells. 

 14. JTIelaiiia araclmoidea. 



Plate II. Fig. 14. 



T. conica, tenui, fusco-cornea ; spira gracili, elevata ; anfr. 12, plicis 

 transversis et liris spiralibus decussatis, lira central! in carinam elevata, 

 subter quam plicse evanescunt; suturis valde impressis; apertura parva, 

 ovata, intiis purpurascente ; coluinella incurva, in sinum angustum 

 producta. 



Shell conic, rather thin, horn-colored; spire slender and 

 much elevated ; whorls 12, very strongly striated and ribbed, 

 particularly the upper ones ; the ribs extend only to a promi- 

 nent, acute carina on each whorl, situated below the middle, 

 between which and the suture below, one or two coarse striae 

 alone are visible ; sutures deeply impressed ; aperture very 

 small, ovate, purplish within ; columella regularly curved, 

 without indentation, and with but a small, very narrow sinus 

 at base. 



Length 1 inch (26 millim.). Diam. 0.28 inch (7 millim.). 



Length of aperture 0.22 inch (oi millim.). 



Breadth of do. 0.15 inch (4 millim.). 



Habitat. A small stream emptying into the Tennessee river, 

 near Loudon, Tennessee. 



Cab. Lye. Fat. Hist., K Y. J. GL Anthony. B. W. Budd. 



Obs. This is one of the slenderest and most elevated of the 

 genus ; more than forty specimens are before me, and they are 

 very constant in all their characters ; it comes nearest to M. 

 striatula Lea by its folds and striae, but should not be confounded 

 with it, being different in every other particular ; the number 

 of whorls is greater by one half, the striatula having only eight ; 

 its proportions are altogether more slender, the striatula stand- 

 ing as 21 to 49, while this is 28 to 100. The present species is 

 also much more folded and rough than the striatula^ which is 



