OBSERVATIONS. 



Inhabits rivers in Munroe cc, Virginia: Mr. Wil- 

 liam B. Rogers. 



MELANIA SEMICOSTATA. 



Plate IX.— Fig. 6. 



description. 



Shell elevated; longitudinally ribbed; whirls con- 

 vex, with fine spiral strise; body whirl without ribs, 

 obscurely striated above, subbiangulated in the mid- 

 dle; aperture large, obliquely elliptical; within bluish, 

 with brown bands. 



observation. 

 Inhabits streams in North Alabama. 



MELANIA ROGERSIl. 



Plate IX.— Fig. 7. 



description. 



Shell subovate, with rather distant prominent spi- 

 ral lines; whirls convex; body whirl ventricose; 

 aperture subovate, hah" the length of the shell; co- 

 lumella obtusely angular at the base. 



Variety A. Destitute of revolving lines; whirls 

 gibbous. 



