OBSERVATIONS. - 
Inhabits rivers in Munroe co., Virginia: Mr. W1L- 
LIAM B. Rocers. 
MELANIA SEMICOSTATA. 
Puate IX.—Fig. 6. 
DESCRIPTION. 
Shell elevated; longitudinally ribbed; whirls con- 
vex, with fine spiral strie; body whirl without ribs, 
obscurely striated above, subbiangulated in the nid 
dle; aperture large, oliauily elliptical; within bluish, 
with brown bands. 
OBSERVATION. 
Inhabits streams in North Alabama. 
MELANIA ROGERSII. 
PLATE IX.—Fig. re 
DESCRIPTION. 
Shell subovate, with rather distant prominent spi- 
ral lines; whirls convex; body whirl ventricose; 
aperture subovate, half the length of the shell; co- 
lumella obtusely aneeular at the base. 
Variety A. Destitute of revolving lines; whirls 
gibbous. 
