TRAPEZIUM. 149 



strong concentric lamellae. The ornamentation is indistinct on the. part above the 

 rounded ridge. Margin of valve crenulate. 

 Measurements : 



(i) (2) (3) (4.) 



Length . 155 . 14 . 13'5 . 12'5 nun. 



Height 12 . 11 . 11 . 10 „ 



Thickness . 10 . 10 . 10-5 . 9 



(1 — 4) Lower Grreensaud, Upware. 



Affinities. — Keeping compared this species with Gardita neocomiensis, d'Orbigny, 

 to which it shows some resemblance in general form. But the faint radial ribs 

 and strong concentric lamella), as well as the character of the hinge, so far as it 

 can be made out, seem to connect this species with Trapezium rather than with 

 Gardita. 



Type. — In the Sedgwick Museum. 



Distribution. — Lower Greensand, Upware. 



Teapezium ? sp. Plate XXIII, fig. 10. 



1883. Cypricardia striata, W. Keeping. Foss., etc., Neoc. Upware and Brickhill. 



p. 119. 



An imperfect left valve from the Lower Greensand of UpAvare, in the Sedgwick 

 Museum, was identified by W. Keeping with Gypricardia striata (Geinitz) * from 

 the Cenomanian of Saxony. The ribs are fewer in number than in the examples 

 of G. striata figured by Geinitz. 



Trapezium trapezoidale (Burner), 1841. Plate XXIII, figs. 17 — 19. 



1841. Crassatella trapbzoidalis, F. A. Bomer. Die Verstein. d. nord-deutscb. 



Kreidegeb., p. 74, pi. ix, 

 fig. 22. 

 ? 1847. A. d'ArcJtiac. Mem. Soc. geol. de France, 



ser. 2, vol. ii, p. 302. 

 1850. Cyprina H. B. Geinitz. Das Quadersandst. oder 



Kreidegeb. in Deutscb- 

 land, p. 158 (partim). 

 1854. Cypricardia A. d'Orbigny. Prodr. de Pal., vol. ii, p. 240. 



1 ' Cbar. d. Scbicht. u. Petrel des siicbs. Kreidegeb.,' pt. 2 (1840), p. 52, pi. x, fig. 3. Modiola 

 carditoides, Geinitz, 'Das Elbthalgeb. in Sacbseu ' (' Palaeontographica,' vol. xx, pt. 1, 1873), p. 218, 

 pi. xlviii, figs. 11 — 13 ; pi. xlix, tigs. 19, 20. 



20 



