PLATE LVIII. 



PAGE 



Figs. 1, la, lb, Ic. Platidia mabylandica n. sp 203 



1. Exterior of ventral valve. Upper Marlboro, 

 la. Interior of the same. 



lb. Exterior of dorsal valve of the same individual. 

 Ic. Interior of the same. 



Figs. 2, 3, 3a. Terebbatula hablani Morton 204 



2i Interior of ventral valve. 3 miles west of Leeland. X 4/9 

 3. Exterior of ventral valve from the same locality. 

 3a. Dorsal aspect of the same individual. 



810 



