74 CRETACEOUS LAIilELLIBllANCHIA. 



bridge Grecnsaiicl (indigenous). Cliloritic Marl of Maiden Bradley, Devizes, 

 Isle of Wight, Urchfont (Wilts), Holj^bourne (Hants), and Eastbourne. Chalk 

 Marl (zone of Schloenbachia varians) of the Isle of Wight, Folkestone, Hunstanton, 

 Lincolnshire, and Yorkshire. Totternhoe Stone of Fulbourn and BurweU. Zone 

 of Uolaster sulnjlohosus (above Totternhoe Stone) of Eversden (Cambs.). 



Fa,}iUi/—¥E'Rm'DM, Zittel. 

 Genus — Geuvillia, M. J. L. Dcfrance, 1820. 



('Diet. Sci. nat.,' vol. xviii, p. 502.) 



Gervii,li.\ sublanceolata (cVOrhiijny), 1850. Plate X, figs. 14 — 10; Plate XI, 



fig. 1. Text figures 7, 8. 



1826. Geevillia aviculoidks, J. de C. Sowerhy. Miu. Couch., vol. vi, p. lO, pi. 



dxi, figs. 1, 2, 3, 5 (not 4), [uou Periia 

 aviculoicles, Sowerby, 1814]. 



1845. — — E. Forbes. Quart. Jouru. Geol. Soc, vol. i, p. 24(5. 



— AvicuLA LANCEOLATA, — Ibid., p. 247, pi. iii, fig. 8. 

 1850. — SUBLANCEOLATA, A. d'Orhujuij. Proilr. de Pal., vol. ii, p. 119. 



1853. Gervilia alpina, F. J. Pidd and W. Roux. Moll. Foss. Gres verts de 



Geneve, p. 496, pi. xli, fig. 3. 



1854. Gervillia anceps, J. Morris. Cat. Brit. Foss., ed. ii, p. 167. 



— AvicoLA LANCEOLATA, Morris. Ibid., p. 163. 



1858. Gervilia anceps, F. J. Fidet and E. Eenevier. Foss. Terr. Ajitien (Mati'r. 



Pal. Suisse, ser. 1), p. 121 , 

 pi. xvii. 

 1865. — — H. Coquand. Mon. Aptieu de I'Espague, p. 145. 



1869. — ALPINA, F. J. Firtd and G. Cainpiche. Foss. Terr. Cret. Ste. Croix 



(Mater. Pal. Suisse, ser. 5), 

 p. 83, pi. civ, figs. 2—4. 

 1902. Gervilleia anceps, F. Freeh. Centralb. fiir Miii.,etc., p. 612 (text-figure). 



Dcticription. — Shell elongate, very oblique, slightly inecjuivalve, the left valve 

 rather more convex than the right. Posterior extremity lanceolate, but rounded. 

 Postero-dorsal margin slightly sinuous. Antero-ventral marginal parts nearly per- 

 pendicular to the plane lictween the valves and slightly concave. Umbones incon- 

 spicuous, almost terminal. Only a very small portion of the valve is seen in front 

 of each umbo; on the left valve this portion is bounded by a linear depression, but 

 on the right valve it is not limited. Tlie median part of each valve is convex, but 

 becomes compressed towards the posterior extremity. Between the convex portion 

 and the hinge-line (posterior to the umbo) is a long, triangular, compressed, wing- 

 like portion, of which tlie inner boundary is not limited, and tlie posterior margin 



