OSTREA. 393 



Zone of Marswpites testudinarius of Farnborough, Ropley, Taplow, and Brighton. 

 Recorded by Rowe from the Sussex and Thanet coasts. 



Uiiitacrinus band of Devizes Road (Salisbury) ; Odeham, Alresford, and Itchon 

 Abbas (Hants) ; Margate. 



Zone of Actinocamax quadratics of Bullington, Ropley, Wield, Andover, and 

 Rottingdean. 



Osteea lunata, Nilssoii, 1827. Plate LX, figs. 1G— 19. Plate LXI, figs. 1—6. 



1816. Osteea canaliculata, J. Sotverby. Min. Conch., vol. ii, p. 81, pi. cxxxv, 



fig. 1. (Non canaliculata, Sowerby, 

 1813). 



1827. — lunata, S. Nilsson. Petrif. Suecana, p. 31, pi. vi, fig. 3. 



1833. — — A. Goldfuss. Petref. Germ., vol. ii, p. 11, pi. lxxv, fig. 2. 



1834. — nasuta, S. G. Morton. Synop. Org. Eemains Cret. U. States, p. 51, 



pi. ix, fig. 6. 

 ? — — mesenterica, Morton. Ibid., p. 51, pi. ix, fig. 7. 



1837. — lunata, W. Hisinger. Lethsea Suecica, p. 49, pi. xiv, fig. 4. 

 1849. — T. Brown. Illustr. Foss. Conch. G-t. Britain and Ireland, 



p. 147, pi. lxi*, figs. 20, 21. 

 1854. — larva, J. Morris. Cat. Brit. Foss., ed. 2, p. 173. 

 1869. — ungulata, H. Coquand. Mon. Ostrea, Terr. Cret., p. 58 (partim), 



pi. xxxi, figs. 6—8 (? 9, 10). 

 ? 1870. — lunata, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch , vol. 



xxii, p. 227. 



1884. — (Alectryonia) larva, C. A. White. Ostreidse of N.America (4th 



Ann. Rep. U.S. Geol. 

 Survey), p. 296, pi. xlii, 

 figs. 2—5, ? 6 (not 7—9). 



1885. — larva var. nasuta, R. P. Whitfield. Brach. and Lamellibr. Raritan 



Clays (Mon. U.S. Geol. 

 Surv., vol. ix), p. 34, pi. iii, 

 figs. 3, 4. 



1894. — lunata, A. Hennia. Geol. F6ren. i Stockholm Forhandl., vol. xvi, 



p. 515. 



1895. — (Alectryonia) lunata, F. Vogel. Holliindisch. Kreide, p. 10. 

 1897. — lunata, A. Hennicj. Revis. Lamellibr. i Nilsson's "Petrific. 



Suecana," p. 14. 

 1907. — nasuta, 8. Welter. Cret. Pal. New Jersey, p. 447, pi. xliii, figs. 7, 8. 

 ? — — mesenterica, Welter. Ibid., p. 446, pi. xliii, figs. 9 — 14. 



Description. — Shell inequivalve, elongated between the umbo and the posterior 

 extremity, curved regularly, usually sickle-shaped. 



Left valve moderately or slightly convex, the part near the umbo being more 

 convex than the later part. Umbo small, usually curved posteriorly, with, in nearly 



