PLATE IV. 



LIMA (continued). 



FIGS. 



1. L. (Plagiostoma) semiornata, d'Orb. Upper Greensand, Ventnor. York 

 Museum. Left valve. Portions of this specimen are enlarged on 

 pi. iii, figs. 16fl-,6. (P. 14.) 



2, 3. L. (Plagiostoma) Meyeri, Woods. Upper Greensand, Warminster. 

 (P. 15.) 



2. Right valve. Museum of Practical Geology, No. 8839. 



3. Left valve. Sedgwick Museum, Cambridge. 



4 6. L. (Plagiostoma) globosa (Sow). Lower Chalk. 4, 5. Totternhoe 

 Stone, Burwell. 6. Zone of Holaster subglobosus, Fulbourn. Sedgwick 

 Museum. (P. 16.) 



4 a, left valve ; b, dorsal view x 1 ; c, portion x 12. 



5 a, right valve ; b, mid- ventral portion x 12. 



6 a, right valve ; b, dorsal view ; c, median portion x 12. 



7 12. L. (Plagiostoma) Hoperi, Mant. (P. 17.) 



7 10. Zone of Actinocamax quadratus, East Harnham. Dr. Blackmore's collection 

 7. Left valve ; 8 a, right valve ; 8 b, anterior area of left valve ; 9 a, left valve 

 9 b, dorsal view ; 10, left valve. 



11. Zone of Belemnitella mucronata, Norwich. Norwich Museum. 11 a, right 



valve ; 1 1 b, anterior area of the same. 



12. Zone of Micraster cor-anguinum, Gravesend. Mr. Dibley's collection. 12 a, left 

 valve ; 12 b, portion x 6. 



13 15. L. (Plagiostoma) cretacea, Woods. Dr. Blackmore's collection. (P. 22.) 



13, 15. Zone of Actinocamax quadratus, East Harnham. 13. Right valve x 1. 



15. Left valve. 



14. Upper part of zone of A. quadratus, Whaddon railway cutting, a, right valve : 

 6, antero-dorsal view x If ; c, portion x 6. 



