﻿SUPPLEMENT TO THE BIVALVIA. 



13 



Spec. Char. C. Testa lavi, convexd, subtrigond, margine antico vix producto, margine 

 postico angulato, subproducto, margine ventrali rotundato." {Morris.) 

 Length, -nyths of an inch ; height, \ an inch. 

 Localities. Bembridge, Hempstead {Forbes). 



There is a considerable difference in the form of this shell from C. obovata, on 

 which account I have kept it specifically distinct. A. large series of each, however, 

 might possibly remove the distinction and unite this with obovata. My specimens show 

 a more rounded form than obovata, with a much depressed umbo and an absence of the 

 strongly angular form of the posterior side of that shell. They are also less triangular 

 and not so inflated. The species has been kept distinct by Messrs. Forbes and Morris, 

 and I have thought it best to follow them in so doing. 



The specimens of this species have undergone considerable erosion of the umbones, 

 so much so that a specimen which I have had represented shows the cardinal teeth 

 standing out prominently, and these are visible even when looking at the exterior of the 

 shell. 



17. Cyrena deperdita, Lam. Tab. B, fig. 10 a — d. 



Cyclas deperdita, Lam. Ann. du Mus., t. vii, p. 425, 1803. 



Cyrena — Desk. Coq. Foss. des Env. de Par., p. 118, pi. xix, figs. 14, 15, 

 1824. 



— — S.Wood. Lond. Geol. Journ., p. 118, 1847. 



— — Morris. Mem. Geol. Surv. (Isle of Wight), p. 15G, pi. vii, fig. 



11 a, b, 1856. 



— — Lowry. Chart Brit. Tert. Foss., pi. ii, 1866. 



— — Sandberger. Land- und Sussw. -Conch., p. 25 1, t. xiv, fig. 3, 1872. 



Spec. Char. " C. Testa ovafo-ventricosd, obliqud, subtrigond, laevigata substriatdve ; 

 umbonibus magnis, injlatis, recurvis ; dentibus cardinalibus tribus valvd sinistra, duobus 

 dextrd ; dentibus lateralibus subaqualibus, lavigatis." (Desh.) 



Length, -§ ths of an inch ; height, y^ths of an inch. 



Localities. Britain: Hordle, Ileadon Hill {Morris). 

 France : Pontoise {Deshages). 



This is an abundant shell at Hordle in the purely freshwater deposit at the cliff of 

 that locality, in association with the remains of the Alligator? Crocodile, Trionyx, Lmgs, 

 Lepidosteus, and sundry Mammalia, as mentioned by me in the ' Lond. Geol. Journ.' 

 (1846), p. 6. 



1 All the vertebrate remains obtained by me from Hordle (which included many besides those figured 

 in the 'London Geological Journal,' and among them the hitherto undescribed jaw of a ftodent and a 

 bone of a Bird) were given by me to the National Collection in the British Museum in 1846. 



