PLATE LVI. 



Osteea (continued). 

 Figs. 



1. 0. vesiculosa (Sow.). Upper Greensand (zone of Schloenbachia rostrata), 

 Dinton. Museum of Practical Geology, No. 259-37. a, left valve; 

 b, posterior view. (P. 374.) 

 2—16. 0. canaliculata (Sow.). (P. 375.) 



2. Gault, Folkestone. Museum of Practical Geology, No. 20819. a, left 

 valve; 6, right valve. 

 3—5. Gault, Folkestone. British Museum, Nos. L 4927, L 23044. 3a, left valve ; 

 36, dorsal view. 4, interior of left valve. 5, interior of right valve. 



6. Upper Greensand (zone of Pecten asper), Warminster. Sedgwick Museum. 



a, left ; b, right valve. 



7. Zone of Holaster subrjlobosus, Burwell. Sedgwick Museum. Left valve. 



8. Melbourn Rock, Hitchin. Sedgwick Museum, a, left valve; b, anterior 



view. 



9. TJintacrinus band, Devizes Road, Salisbury. Dr. Blackmore's Collection. 



Left valve. 

 10, 11. Zone of Adinocamax quadratics, East Harnham. Dr. Blackmore's Collec- 

 tion. 10a, left valve; 106, portion x 5. 11a, right valve and part of 

 left valve ; 116, posterior view. 



12. Same horizon and collection. West Harnham. a, left valve ; b, posterior 



view. 



13. Zone of Adinocamax qitadratus, Marwell, Hants. Sedgwick Museum. 



Left valve. 

 14, 15. Zone of Belemnitella mucronata, Norwich. Dr. Rowe's Collection. 14a, 

 15a, left valves; 146, 156, right valves and parts of left valves. 



16. Zone of Belemnitella mucronata, Alderbury Well. Dr. Blackmore's Collec- 

 tion. Left valve. 



] 7—19. 0. semiplana, Sow. Upper Chalk. (P. 379.) 



17. Zone of Belemnitella mucronata, Norwich. Norwich Museum, No. 2135. 

 Left valve. 



18. Same horizon, locality and museum. No. 2130. a, right valve ; 6, left 

 valve. 



19. Uintuerinus band, Thanet coast. Dr. Rowe's Collection, a, right valve ; 

 6, left valve. 



