55 
obliquely elliptical; less than half the length of the 
shell. 
OBSERVATIONS. 
Inhabits with the preceding species. The spire is 
very regularly conical, and the base strongly ribbed, 
MELANIA NASSULA. 
Plate VIII. — Fig. 9. 
DESCRIPTION. 
Shell elevated, whorls convex or subangulated, 
with longitudinal ribs, crossed by numerous spiral 
elevated lines, about seven on the penultimate whorl, 
and about eleven on the body whorl; suture impress- 
ed; apex much eroded. 
OBSERVATIONS. 
Inhabits the limestone spring at Tuscumbia, Ala- 
bama. Immense numbers of this pretty species con- 
gregate on the rocks where Spring Creek finds a 
passage through a cavern of the carboniferous lime- 
stone. 
MELANIA CYLINDRACE A. 
Plate VIII. — Fig. 10. 
DESCRIPTI ON. 
Shell subcylindrical, smooth, with a short spire, 
