420 CRETACEOUS LAMELLIBRANCHIA. 



? 1866. Ostrea (Exogtea) sp. cfr. sigmoidea, K. A. Zittel. Bivalv. d. Gosaugeb. 



(Denksclir. d. k. Akad. Wissensch. 

 Wien, Math.-nat. CI., vol. xxxv, 

 pt. 2), p. 123, pi. xix, fig. 5. 

 1869. — sigmoidea, H. Coquand. Mon. Ostrea, Terr. Crt't., p. 93, pi. xxxiv, 



figs. 5 — 7 bis. 

 1872. — (Exogyra) sigmoidea, H. B. Geinitz. Das Elbthalgeb. in Sachsen 



(Palaeontographica, vol. 

 xx, pt. 1), p. 186, pi. xli, 

 figs. 14—27. 

 ? 1882. Exogyra cfr. sigmoidea, B. Windmbller. Jahrb. d. k. preuss. geol. 



Laiidesaiist. fur 1881, 

 p. 30. 

 1888. sigmoidea, G. Miiller. Ibid, fur 1887, p. 401. 



1911. — — A. Fritsch. Stud, im Geb. d. bohmisch. Kreidef., 



Korycaner Schicht., p. 46, fig. 209. 



Remarks. — The only English specimen I have seen is aright valve collected by 

 Mr. LI. Treacher. The strong carina, the concentric ribs on the anterior slope, 

 the more sinuous and more oblique posterior margin and growth-lines distinguish 

 this species from the Bauliniana form of E. conlca. The inner margin of the 

 valve is finely crenulate. The types came from the Lower Planer-kalk of Schilling 

 near Bilin. 



Distribution. — Zone of Micraster cor-anguinum of Boxford, Berkshire. 1 



Family— RADIOLITID^E, Gray. 



[Omitted from Vol. II, p. 210.] 



Genus — Durania, H. Douville, 1908. 



{' Bull. Soc. geol. de France,' ser. 4, vol. viii, p. 309, and ' Mem. Soc. geol. de France, Paleont.,' vol. 



xviii, 1910, p. 23.) 



Durania Mohtoni (Mantell), 1833. 



1833. Hippurites Mortoni, G. Mantell. Geol. S.E. England, p. 130. 

 1836. Conia, B. Hudson. Loudon's Mag. Nat. Hist., vol. ix, p. 104, fig. 19. 

 1838. Sph^rulites Mortoni, J. E. Gray. Mag. Zool. Bot., vol. ii, p. 228. 

 1850. Hippurites Mortoni, J", de C. Soiverby, in F. Dixon. Geol. Sussex, p. 354 



(p. 385, ed. 2), pi. 



xxvi, figs. 1, 2, 4. 



1 White and Treacher, 'Quart. Journ. Geol. Soc.,' vol. lxii (1906), p. 518. 



