I 12 



CRETACEOUS LAMELLIBRANCHIA. 



the postero-dorsal side of the latter, but in examples in wliich the umbones are 

 more anterior in position the median cardinal is dorsal to the anterior cardinal, 

 and is almost continuous dorsally with the posterior cardinal tooth. 

 Measurements : 



(2) (3) (4) 



104. . 99 . 98 . 



90 . 86 . 86 . 



(1—8) Blackdown. 



Length 



(i) 

 103 



Height . 92 



(5) 



(0) 



(7) 



(8) 



96 . 



, 89 



, 87 



. 82 mm 



86 . 



, 79 , 



, 79 



• 70 „ 



Affinities. — Specimens of Cyprina from the Aptian and Gault of the Perte du 

 Rhone and Ste. Croix were referred by Pictet, Roux, and Renevier, to G. ervyensis, 

 Leymerie, but were subsequently identified with C. angulata by Pictet, Renevier, 



\ 



Fig. 23. — Qyprvna (Venilicardia) angulata (Sow.). Upper Greensand, Blackdown. Museum of Practical 

 Geology, No. 18098. Eight valve, and anterior view of both valves, x ±. 



and Campiche. 1 Pictet and Campiche, after an examination of specimens from the 

 Gault of Nievre and Yonne, came to the conclusion that 0. ervyensis, as described 

 and figured by Leymerie- and d'Orbigny, 3 must be regarded as a synonym of 

 G. angulata. I have had no opportunity of comparing French specimens with 

 examples from Blackdown, but so far as I can judge from the figures of G. ervyensis 

 there appear to be some differences, consequently I do not at present feel justified 

 in including C. ervyensis as a synonym of G. angulata. 



1 Pictet and Roux, 'Moll. Foss. Ores verts de Geneve' (1852), p. 444, pi. xxxiv, fig. 1. Pictet and 

 Renevier, ' Foss. Terr. Aptien ' (' Mater. Pal. Suisse,' ser. 1, 1850-58) , pp. 75, 177. Pictet and Campiche, 

 'Terr. Oct. Ste. Croix' ('Mater. Pal. Suisse,' ser. 4, 1865), p. 221. 



2 ' Mem. Soc. geol. de France,' vol. v (1842), pp. 5, 25, pi. iv, tigs. 6, 7. 

 s ' Pal. Franc. Terr. Crct.,' vol. iii (1844), p. 102, pi. cclxxiv. 



