PLATE XII. 



G-ervillia (continued). 

 Figs. 



1 — 5. G. Forbesiana, d'Orb. Gault, Folkestone. (P. 85.) 



1. Sedgwick Museum. Left valve, x f . 



2. British Museum, No. L 4918. Left valve. 



3. Sedgwick Museum. Right valve. 



4. „ „ Left valve. 



5. ,, „ Hinge of right valve, x 1|. 



Genus — Perna, Bruguiere. 



6—9. P. Raaliniana, d'Orb. Gault, Folkestone. (P. 92.) 



6. Sedgwick Museum. Left valve. 



7. „ ,, a, right valve ; b, anterior view. 



8. Museum of Practical Geology, No. 1605. Left valve. 



9. „ „ „ No. 12638. Left valve. 



10. P. sp. Gault, Folkestone. Sedgwick Museum. Left valve. (P. 94.) 



Gen us — Pinna, Lin nssus. 

 11-15. P. Bobinaldina, d'Orb. Lower Greensand. (P. 96.) 



11. Isle of Wight. Bristol Museum. Right valve. 



12. Crioceras Beds, Atherfield. British Museum, No. 48626. Portion of dorsal 



half of left valve, x 3. 



13. Per/ia-bed, Atherfield. Sedgwick Museum. Ventral part of left valve. 



14. Crackers, Atherfield. Museum of the Geological Society, No. 2100. Right valve. 



15. Peraa-bed, Atherfield. Sedgwick Museum. Left valve. 



