52 
OBSERVATIONS. 
This singular shell approaches the genus Ancido- 
tus, in form, but the aperture is that of a Melania. I 
found it adhering to logs in the Tennessee river, at 
Florence, where it is abundant. My friend, William 
Hodgson, jr. found it also in the Holston river, in 
Tennessee. 
MELANIA PYRENELLA. 
Plate YIII. — Fig. 5. 
DESCRIPTION. 
Shell elevated, with flattened whorls, having an 
obsolete spiral line on each; suture impressed; body 
whorl angulated; angle defined by a prominent line; 
base hardly convex; labrum angulated near the cen- 
tre; aperture patulous; columella obtusely rounded 
at the base, 
OBSERVATIONS. 
Inhabits streams in North Alabama. The aper- 
ture is remarkably patulous and the labrum pro- 
foundly angulated. 
MELANIA BITiENIATA. 
Plate VIII. — Fig , 6. 
DESCRIPTION. 
Shell conic, with convex whorls; spire short; one 
