PLATE IX. 



Pteeia (continued). 

 Sub-Genus — Pseudopteka, Meek. 



FIGS. 



1. P. (Pseudoptera) suhdepressa (d'Orb.). Lower Greensand (Crackers), 

 Atherfield. The Type. Museum of the Geological Society, No. 

 2050. a, left valve ; h, portion of posterior ear x 4. (P. 63.) 



2 — 4. P. {Pseudoptera) anomala (Sow). Upper Greensand. 2, 3, Blackdown. 

 4, Haldon. (P. 64.) 



2. The Type. Bristol Museum, a, left valve; 6, postero-dorsal view; c, portion 



of ridge X 4^; d, portion of posterior ear x 4. 



3. Britisli Museum, No. L, 16876. a, left valve ; 6, antero-veutral view. 



4. British Museum, No. L, 16869. a, left valve x 2; h, portion near the middle 



of the valve x 8. 



5 — 10. P. {Pseudoptera) haldonensis, Woods. L^pper Greensand, Haldon. 

 Left valves. (P. 66.) 



5. British Museum, No. L, 16800. 



6 a. „ „ „ L, 16759 ; h, ventral portion x 3. 



7. „ „ „ L, 16868. 



8 a. „ ,, ,, L, 16868 ; b, antero-veutral view ; c, middle part of 



antero -ventral side x 6. 

 9. Sedgwick Museum, Cambridge. 

 10. British Museum, No. L, 16805. x 2. 



11, 12. P. {Pseudoptera) gaulfina, Woods. Gault, Black Ven. Left valves. 

 (P. 67.) 



11a. Museum of Practical Geology, No. 10780 ; 11 6, median portion x 6. 

 12 a. Sedgwick Museum ; 12 h, median portion x 3. 



13 — 19. P. {Pseudoptera) coerulescens (Nilsson). Upper Chalk. Left valves. 

 (P. 67.) 



13 — 15. Zone of A. quadratus. East Hamham. Dr. Blackmore's collection. 13 x I5. 



15, median part x 4. 

 16. Zone of B. mucronata. Clarendon. Dr. Blackmore's collection. 

 17 — 19. Zone of .B. H)!(cro?!a/a, Norwich. Norwich Museum. 17n x 2; 17 6, median 



portion x 6- 19a, x \\; 19 6, portion witli rilis x 4. 



