132 EOCENE MOLLUSCA. 



The French specimens of the Cyprcea tuberculosa are smaller and less triangular in 

 form than our English shells ; and the flattened posterior extremity is circumscribed 

 by two lateral callosities which rise, one on each side, towards the back. This 

 singular character, which forms a prominent feature in the specimen figured by 

 M. Deshayes, and which I am assured by that gentleman is constant in the French 

 shells, is wanting in the very few English specimens I have seen. Notwithstanding 

 these differences, the English shells present such close affinities to the French 

 specimens, that they must be regarded rather as a strongly marked local variety than 

 as a distinct species. The dorsal tubercles, from which the specific name is taken, are 

 stated by Mr. Sowerby not to be a constant character; they certainly appear to vary 

 much in size and position, for in the figure and description given by M. Deshayes 

 they are represented as of considerable size, and as ranged longitudinally about the 

 middle of the shell ; while in Duclos's original figure, they appear to be much 

 smaller, and are placed transversely near the posterior extremity. The English 

 specimen now figured, presents an even surface ; but one, formerly in Mr. Bowerbank's 

 museum, and which, unfortunately, has fallen to pieces, had a single large tubercle 

 near the middle. 



With regard to the genus to which this singular shell should be referred, a difference 

 of opinion exists. The absence, or nearly obsolete condition, of the columellar teeth 

 would seem to require that it should be placed, as in fact all the French authors have 

 placed it, among the Ovules; but the pyriform shape, the aperture, and the general aspect 

 of the shell belong rather to C'ypraa. Dr. Gray has pointed out the analogy between 

 it and the tuberculated variety of the recent C. mus, and asserting in fact, that 

 M. Deshayes's specimen has a very few obscure teeth on the lips, he has stated that, in 

 his opinion, the shell is evidently a cowry, an opinion from which Mr. George Sowerby 

 has not dissented. On this authority, I have retained the shell in the present genus, 

 of which, as Mr. James Sowerby has suggested, it may form with C. mus, a sub-genus. 



Size. — Axis, 6 inches and 6-10ths; diameter, 5 inches. 



Localities. — Bracklesham Bay, where it is rare. French .- Retheuil, Cuise-Lamotte, 

 Pierrefonds, (Oise), (fide D'Orb). 



Section — Trivia. 



No. 76. Cypr^ea platystoma. F. E. Edwards. Tab. XVII, fig. la— -f. 



C. testa parvd, ovato-oblongd, ventricosd, antice attenuatd, transversim lineatd, apice 

 elevaio ; lineis angulosis, numerosis, regv.laribus, sulco dorsali perspicuo, mediano, interrupts ; 

 spatiis inter lineas concavis ; aperturd lata, postice sub-productd, Jlexuosd, canaliculatd, 

 antice brevi latogue canali exeunti, vix emarginatd ; labro extus late marginato, in^ medio 

 leviter arcuato. 



Shell small, ovately oblong, ventricose, attenuated in front, almost pyriform ; trans- 



