SUPPLEMENT TO ISAAC LEA'S PAPER ON UNIONID.E. 69 



Unio sudus, Lea. PI. 21, fig. 7. Pouch-shape; dorsal line rather short and 

 nearly straight ; side margins gently curved, flattened above ; basal margin nearly 

 round ; color clear white. Has no hooks. Columbus, Georgia. 



Unio fallax, Lea, PI. 21, fig. 8. Pouch shape; dorsal line rather short and 

 straight; side margins very slightly curved; basal margin nearly round; color 

 clear white. Has no hooks. Columbus, Georgia. 



Unio Claibornensis, Lea. PI. 21, fig. 9. Narrow pouch-shape; dorsal line 

 rather short and straight ; side margins straight ; basal margin well curved ; color 

 nearly clear white; granules very small. Has no hooks. Columbus, Mississippi. 



Unio gibbosus, Bar. PI. 21, fig. 10. Widely pouch-shape; dorsal line long 

 and straight ; side margins slightly curved ; basal margin round ; color clear white. 

 Has no hooks. Columbus, Mississippi. 



Unio Othcaloogensis, Lea. PI. 21, fig. 11. Subrotund ; dorsal line long, 

 slightly curved upwards; side margins well bowed; basal margin round; color 

 clear white. Has no hooks. Othcalooga Creek, Georgia. 



Unio tortivus, Lea. PI. 21, fig. 12. Subrotund; dorsal line rather long and 

 straight; side margins regularly rounded; basal margin round; color clear white. 

 Has no hooks. Columbus, Georgia. 



Unio purpuratus. Lam. Pi. 21, fig. 13. Wedge-shape; dorsal line short and 

 straight ; side margins at the middle curved outwards, towards the base curved 

 inwards, at the base much curved outwards ; basal margin well curved, wider than 

 dorsal, forming acute angles with a minute hooklike process on each angle ; clear 

 white. Hooklike processes very small — four — one on each angle of the basal mar- 

 gin. Both valves inflated, being opened at both sides ; color light brown ; granu- 

 lations indistinct. «, an oblique view showing the interior and two hooks at the 

 base: & is a side view showing two of the four hooks: c is the broad side view: 

 d shows the end of a valve with the two hooks. Columbus, Mississippi. 



Unio Tappanianus, Lea. PI. 21, fig. 14. Subtriangular ; dorsal line long, 

 slightly curved upward in the middle; side margins much inflated above and nearly 

 straight below, forming an obtuse angle below; basal margin with a serrated obtuse 

 angle. Has well developed hooks ; color light brown. Columbia, Pennsylvania. 



Margarita Spillmanii, Lea. PI. 21, fig. 15. Subtriangular; dorsal line very 

 long and nearly straight, slightly raised in the middle; side margins much inflated 

 above and slightly curved below ; basal margin rounded, furnished with imperfect 

 hooks ; color light brown. Columbus, Mississippi. 



