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. 16 a, b. (P. 14.) 



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

 (P. 15'.) 



2. Eight 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 H ; 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. I. (Plagiostoma) Hoperi, Mant. (P. 17.) 



7 — 10. Zone of Actinocamax quadratics, 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. Eight valve x 1£. 

 15. Left valve. 

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

 b, antero-dorsal view x \\ ; c, portion x 6. 



