CYPRINA. 133 



CvnjTXA SKDdwicKT (Wallrr), 18(;(;. Plate XIX, fi^'. 14. Plate XX, figs. 1-5. 



186C. Sph^ra Sedgwickii, ,7. F. WnUer. Ann. Mag. Nat. Hist., ser. 3, vol. 



xviii, p. 380, j>l. xiii, figs. 1, 2. 

 1867. CvPEiNA ANGULATA, var., JT. G. Seelcy. Ibid., ser. 3, vol. xx, p. 27. 

 1875. — Sedgwickii, W. Kcephuj in T. G. Bouncy. • Cambridgosliiro 



Geology,' p. 68. 

 1883. — — W. Keeping. Foss., etc., Neoc. Upwarc and Brick- 



hill, p. 123, pi. vi, fig. 12. 



Description. — Shell more or lef?.'? oval, sometimes suli-triangiilar, rounded, inflated, 

 slightly or moderately inequilateral ; length as a rule not greatly exceeding the 

 height. Lunular margin of moderate length, concave. Anterior margin rounded, 

 passing gradually into the convex ventral margin. Postero-dorsal margin moderately 

 convex. Umbones prominent, l)road, curved inward and forward. Carina absent 

 or indistinct. Postero-dorsal region convex, rounded. Lunule large, ovate, 

 bounded by a faint groove. Escutcheon long, bounded by a more or less distinrf 

 carina. Ornamentation consists of growth-lines. 



Meafivrcments 



(1 — 9) Lower Greensand, Upware. 



Affinities. — This species is closely related to, and may perhaps be only a local 

 variety of G. Sanssuri (see above). The chief points in which it differs from the 

 latter are (1) the carina is absent or indistinct, (2) the posterior margin is 

 relatively higher, (3) the valves are usually more inflated, (4) the shell is usually 

 less triangular in outline and less inequilateral. 



RemarliS. — The examples of C. Se(tgn-irl-i vary in relative height and length, 

 and consequently in outline. The longer forms approach C. Savssiiri more nearly 

 than the shorter forms. 



This species was placed in the genus Spha-ni by '^\v. .1. F. Walker, l)ut was 

 subsequently referred to Gijimiia by Seeley and by "W. Keeping. 



Type. — From Potton, in Mr. J. F. Walker's collection. 



Distnhutio)). — Lower Greensand of Upware and Potton. 



rvrRiXA oi'.xrs.v, Kerpiurj, 1883. Plate XX, fig. <>. 



1883. Cyprina outusa, TT. Keepimj. Foss., etc., Neoc. Upware and Brickhill. p. 



124, pi. vi, fig. 13. 



18 



