152 EOCENE MOLLUSCA. 



the ribs, wliich in this species are free from irabrieations, nodules, or rugosities of any 

 kind, ratlier a rare circumstance with species in this genus. 



Fig. 12 of the same plate represents a specimen from High Cliff, Barton, which, I 

 think, may be considered a variety of this species ; it has fewer ribs and wider spaces, 

 but it is equally unarmed. 



16. Cardita sulcata, Solander. Tab. XXII, fig. \, a,h. 



Chama sulcata, Sol. (in Brander). Foss. Hanton., pi. 7, fig. 100, 1776. 

 Venericardia cor-avium, Lamarck. An. du Mus., t. vii, p. 5S, No. 7, 1806. 



— — Desk. Coq. foss. des Euv. de Par., t. i, p. 156, pi. 24, 



figs. 6—8, 1824. 



— GLOBOSA, J. Sow. Min. Conch., t. 289, fig. 1, 1821. 

 Cardita cor-aveum, cCOrh. Prod, de Paleont., t. 11, p. 423, No. 1613, 1850. 



— sulcata. Id. 



— — Desh. An. sans Vert, du Bass, de Par., t. i, p. 768, 1858. 



Spec. Char. C. Testa rotundato-glohosd, cordiformi, turgidd, incequilaterali, radiatim 

 costatd, costis 16 — 20, elevatis, rugosis, convexis, imbricato-squamosis vel nodulosis ; lunula 

 lata, profunda ; umbonibus incurvis. 



Shell roundly globose, heart-shaped, tumid, inequilateral; costated, ribs 16 — 20, 

 elevated, convex, and rugose, covered with coarse imbrications or nodules ; lunule broad 

 and deep ; beaks incurved. 



Diameter, f of an inch, nearly. 



Localiti/. Barton. 



France : Ezanville, &c.. Sables moyens {Beshayes). 



Prof. Morris and M. Deshayes have both, and I think very justly, restored to this 

 species the name originally given to it by Solander. Probably Lamarck was not aware 

 that his species had been found in England, or had been figured and described in an 

 English work. 



This is most abundant as individuals, at Barton, where it rany be considered as one of 

 the characteristic species of that deposit. The reason why this appears not to have been 

 referred to cor-avium by Mr. Sowerby was a difference in the hinge between the French 

 and English shells ; but this is a variation that may be observed among a large suite of 

 specimens of the British fossil, which will be found to exhibit the broad hinge as well as 

 the narrow one, and I believe with the above-mentioned authors that they constitute but 

 one species. There is a variety at the same locality which differs in having the ribs more 

 distinctly covered with nodules, whereas in the typical form the ribs are more rugose and 

 without distinct tubercles. Var. /3 of J. Sowerby makes an approach towards C. 

 Davidsoni, in which the ribs are sharper. 



