PLATE VI. 



PIGS. 



1-3. Tmgonia van Sharpe 110 



1. Left valve, dorsal aspect; !, umbonal region of the same 

 valve, x 2. Three hundred yards below Addo Drift (Tunbridge's), 



left bank of Sunday's River (41h). 



2. Right valve; 2, dorsal aspect; 2b, frontal aspect. Same 

 locality (40h). 



3. Interior of a right valve. Same locality (42h). 



4, 5. Trigonia stowi sp. nov. ... ... 



4. Right valve ; 4, frontal view ; 4&, dorsal aspect of the umbonal 

 region of right valve and fragment of left valve, showing details 

 of sculpture. Above Modder Drift, Sunday's River. In the col- 

 lection of the Geological Society of London (No. 12006). 



5. Left valve. From the South African Museum collection ; 

 probably Sunday's River. 







