16 EOCENE MOLLUSCA. 
dextraé posterioribus dentibus duobus bifidis, dentibus lateralibus inequalibus, levigatis ; 
nymphis depressis. 
Length, 24th of an inch ; height, 2 inches. 
Localities. Britain: Hempstead, Bembridge (Fordes). 
(and var. Wrightii) Headon beds, I. of Wight. 
This is a large and handsome shell, and deserving of the name given to it by 
Mr. Sowerby, and I believe it is abundant at the above localities. It somewhat resem- 
bles C. Lamberti, Desh., p. 495, pl. xxxix, figs. 9, 10, but differs in several particulars 
from the figure and description of that species, which has a much longer fulcrum or 
support for the ligamentous connector. 
The shell figured as C. Wrightii, Forbes, in the * Memoirs of the Geol. Survey,’ is 
there regarded by Mr. Morris as a variety only of pulchra ; and following the opinion of 
so sound an authority, I have not given Wrightii here as a separate species. 
we 
wo 
2. CYRENA ARENARIA ?, Fordes. ‘Tab. B, fig. 8 a, 0. 
Cyrena AneNnanta, Morris, Catal. Brit. Foss., 2nd edit., p. 199, 1854. 
— — Forbes. Mem. Geol. Surv., Isle of Wight, p. 88, 1856. 
Spec. Char. C. Testd suborbiculari, subaquilaterali, tenui, concentricé et irregulariter 
striata, umbonibus depressiusculis, ared cardinali angustd ; dentibus lateralibus elongatis 
inequalibus. 
Diameter, 1%ths of an inch. 
Locality. Headon Hill (S. Wood). 
The present shell was found by myself at Headon Hill half a century ago, before any 
divisions of the Isle of Wight series had been worked out, and I am unable to say to 
which division of the fluvio-marine group it may belong. I have given it under the 
above name with doubt, in consequence of Forbes’ species arenaria not having been 
figured or described. The hinge of the specimen figured is much narrower than is that 
of pulchra, and the shell itself is much thinner than in that species. ‘I'wo of the cardinal 
teeth in each valve are bifid, but the lateral teeth are narrower and more elongated than 
those of pulchra, but none of them are quite perfect. 
93. Cyrena TENERA, S. Wood. ‘lab. B, fig. 9. 
Spec. Char. (C. Testi tenerd, ovato-oblongd, lavigaté ; valde inequilaterali, 
catremitatibus obtusis, umbonibus minimis depressis, obliquis; cardine angusto. 
