PLATE XII. 



GeRVILLIA (mill hilled). 



Fias. 

 I — "), ff. Fnrhrsi,nin, (VOrl). Gault, Folkestone. (P. 85.) 



1. Sedgwick Museum. Left valve, x ,f- 



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



3. Sedgwick Museum. Eight valve. 



4. ,, „ Left valve. 



5. „ „ Hinge of right valve, x Ih. 



Genua — Perna, rinigiiiere. 



0—0. P. naiiliiiunn,, d'Orh. Ganlt, Folkestone. (P. 92.) 



6. Sedgwick Museum. Left valve. 



7. ,, ,, (J, right valve ; fc, anterior view. 



8. Museum of Practical Geology, No. 1G0.5. Left valve. 



9. „ „ „ No. 12638. Loft valve. 



10. J', s\^. (jiatilt, Folkestone. Sedi^wick Museum. Left valve. (I'. 'M.) 



npnuf! — Pinna, Jjvntn'va. 



1 t-L^. /'. liiihiiiiildiiin, d'Orl). Lower (ireensand. (P. '.((i.) 



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



12. Crioceras Beds, Atherfu'ld. British Museum, No. 48620. Portion of dor.sal 



half of loft valve, x 3. 



13. PcrHrt-bod, Athorfield. Sedgwick Museum. Ventral part of left v.alve. 



14. Crackers, Atherfield. Museum of the Geological Society, No. 2100. Kii^'ht valve. 

 1-5. Perna-hei], Atherfield. Sedgwick Museum. Left valve. 



