ALBIAN FOSSILS DISCOVERED AT OkEFORD FITZPAINE. 91 



smaller nuculoid shell which may represent the young form of 

 this species. These latter occur in the sandy-rock base of the 

 H. interruptus zone. 



RANGE OF SPECIES. Albian. 



LOCALITIES. Folkestone, Black Ven, Maidstone, Devize?, 

 Norfolk, Cambridge, &c. ; Wissant, d'Ervy, &c. 



EXOGYRA CANALICULATA, J. Sowerby. 



Plate iii., figs. 7-8. 



Chama canaliculata, J. Sowerby : Mineral Conchology, 1813, 

 Vol. 1, PI. 26, fig. 1, p. 68. 



Gryplicea canaliculata, J. de C. Sowerby : Mineral Conchology, 

 1829, Vol. 6, p. 218. 



Ostrea lateralis, Nilsson : Petrificata Suecana Cretacse, 1827, 

 Plate 7, figs. 7-10, p. 29. Goldfuss : Petrefacta Germanise, 1833, 

 Vol. 2, PL 82, fig. 1, p. 24. 



Exogyra parvula, Leymerie : Mem. Soc. Geol. France, 1842, 

 Vol. 5, PI. 12, figs. 8-9, p. 16. 



Ostrea canaliculata, Orbigny : Paleontologie Franchise, Terrains 

 Cretaces, Lamellibranchia, 1846, PI. 471, figs. 4-9, p. 709. 



Gryphcea canaliculata, Brown : Illustrations Fossil Conchology, 

 1849, PI. 61, fig. 18, p. 149. 



Ostrea canaliculata, Pictet and Roux : Mollusques Gres Verts, 

 Perte du Rhone, 1853, PI. 50, fig. 2, p. 522. Coquand : Mono- 

 graphic genre Ostrea, 1869, PI. 45, figs. 13-14 ; 47, figs. 7-10; 52, 

 fig. 13; 60, figs. 13-15, p. 128. 



Ostrea lateralis, Ccquand : Hid, PI. 18, fig. 12, p. 96; and 

 PI. 30, figs. 10-14. 



This shell shows the typically spiral umbones of Exogyra, under 

 which genus it is now placed instead of Ostrea, as in my former 

 paper. It is a small form, with a deep lower valve, the other being 

 fiat and operculiform. Both valves are ornamented with regular 

 concentric plications, the convex one having a postero-laieral 

 expansion in the adult state, which is also feebly expressed in the 

 flat valve. The specimen figured is a detached and well-preserved 



