﻿JO TRUNCir,LA 



pcnita. they are rather narrower and more compressed in 

 front. The posterior end is somewhat evenly rounded instead 

 ■of being obHquely truncate, so that the marsupium does not 

 extend quite as far back as the hinder part of the shell on the 

 meridian line, or at least no farther. I am inclined to believe 

 that the male shell is generally somewhat wedge-shaped when 

 viewed from above, being most inflated at the posterior ridge. 



Truncilla METASTKiATA (Conrad). 



Shell moderately solid, subinflated, elliptic-triangular to sub- 

 quadrate, slightly inequilateral, beaks moderately full; surface 

 delicately concentrically striate, radially striate behind ; epi- 

 -dermis smooth, shining, yellowish or greenish-yellow with 

 numerous faint, narrow, green rays ; pseudocardinals subcom- 

 pressed, rough ; laterals short ; nacre whitish or bluish-white. 

 Male shell elliptic-triangular, slightly striate behind. Female 

 shell somewhat quadrate, narrower in front, with a rounded 

 posterior end ; marsupial swelling full, not placed at the ex- 

 treme posterior part of the shell, strongly sculptured. 

 Length (male) 31, height 23 mm. 

 Length (female) 28, height 20, diam. 15 mm. 

 Black Warrior River and Woodville, Alabama. 

 Type locality, Black Warrior River at Blount Springs, Ala. 

 Unio metastriatns Conrad, Mon., XII, 1840, p. 104, pi. LVii, 



fig. 2. 

 Truncilla metastriata Simpson, Syn., 1900, p. 519. 



I am much in doubt as to the validity of this species as it is 

 very likely nothing more than a variety of T. compacta. A fe- 

 male shell before me is more delicate than females of that 

 species, more polished and is finely rayed throughout. 



Truncilla modicklla (Lea). 



Shell small, inflated, solid, subtriangular or subrhomboid, 

 Inequilateral; beaks apparently full and elevated; surface al- 

 most smooth ; epidermis greenish-yellow to greenish-brown, 

 •scarcely shining; teeth somewhat roughened; laterals short, 

 double in the left valve, semi-double in the right ; beak cavi- 



