PLATE III. 

 Lima {continued). 



Fios. 



1 — i. L. asjjera (Mant.). Lower Chalk (Totternhoe Stone). 1 — 3. Sedgwick 

 Museum. 4. York Museum. (P. 8.) 



1. Burwell. a, right valve x 1|; 6, median portion x 6. 



2. Cherry Hinton. Left valve. 



3. Burwell. Anterior area of right valve x 1 j. 



4. Burwell. Right valve. 



5 — 9. L. (Plagiostomn) suhrigida, Rihner. Claxby Ironstone, Benniworth 

 Haven. Sedgwick Museum (P. 10.) 



5 a. Right valve ; h, antero-dorsal view. 



6. Left valve. 



7. Antero-ventral part of right valve. 



8. Portion of right valve x 6. 



9. Left valve. Portion of a young individual x 8. 



10. L. {Phtgiostoma) sp., cf. Orhignyana, Matheron. Lower Greensand (Ferru- 

 ginous Sands), Slianklin. British Museum, No. L 15754. a, right 

 valve X 1^ ; h, anterior view of the same X 1^ ; c, portion x 6. 

 (P. 12.) 



11 — 13. L. (Plagiostoma) vUlersensis? Pict. and Camp. Lower Greensand, 

 Faringdon. Sedgwick Museum. (P. 13.) 



11a, left valve x l.V; h, portion x 4. 



12 a, left valve x l.i; 6, anterior view, natural size. 



13. Left valve. 



14 — IG. L. (Plagiostoma) semiornata, d'Orb. Upper Greensand, Ventnor. (P. 14.) 



14. York Museum. Left valve. 



15. Sedgwick Museum. Right valve. 



16. York Museum. Left valve, a, anterior part x 3 ; b, postero-dorsal part x 3. 



