* l 2 



CRETACEOUS LAMELLIBRANCHIA. 



Fio. 11. — Gervillia alseformis (Sowerby). Right valve, and umbo and ligament area of the left valve 

 of the specimen shown in figs. 9, 10. x f. 



Figs. 12, 13.— Gervillia alseformis (Sowerby). Lower Greensand (Crackers), Atherfield. Sedgwick 

 Museum. 12. Left valve. 13. Right valve, x J. 



