CARDIUM.— Plate V. 



Species 27. (Mus. nobis.) 

 Cardium hians. Card, testa ovato-globosd, subobliqud, 

 subcequilaterali, wntricosissimd, postice latissime Mante, 

 radiatim costatd, costis vicenis, angustis, subobtusis, 

 mediums lirdparvd obtuso-cortvexd interveniente, anticis 

 squamiferis, postieis mvicem compresso-planulatis, ser- 

 rato-spinosis, spinis valM irregularibus ; fuscescente, 

 ustulato-fusco fasciatim variegaid, interstitiis postico- 

 medianis mgrvcante-fuscis, costis postremis subrosaceis, 

 spinis albis, quasi eburneis. 

 The gaping Cockle. Shell ovately globose, rather ob- 

 lique, nearly equilateral, very ventricose, very widely 

 gaping posteriorly, radiately ribbed, ribs twenty in 

 number, narrow, rather blunt, middle ribs with a 

 small obtusely convex ridge running between them, 

 anterior ribs squaniiferous, posterior conipressly flat- 

 tened one upon the other, serrately spined, spines 

 very irregular ; brownish, the posterior-middle inter- 

 stices blackish brown, extreme posterior ribs pinkish, 

 spines white, like ivory. 

 Brocciii, Conch. Foss. Subap., vol. ii. p. 508, pi. 13, f. 6. 

 Cardium Indicum, Lamarck, Sowerby. 

 Cardinal Burdigalinum (fossil), Lamarck. 

 Ilab. Algeria. 



This rare and very remarkable shell is one of consider- 

 able importance in the genus on account of its being the 

 recent analogue of a fossil species described, and most ac- 

 curately figured by Brocchi. Lamarck published the de- 

 scription of an odd valve which came into his possession, 

 under the name of Cardium Indicum, and another valve 

 was subsequently figured by Sowerby with the same title 

 in the Conchological Illustrations. M. Deshayes, however, 

 in his invaluable edition of Lamarck's ' Anim. sans vert.,' 

 says, " Cette belle et precieuse coquille est reellement le 

 type vivant d'une espece bien connue a l'etat fossile, et 

 dont Brocchi a donne une bonne figure sous le nom de 

 Cardium Mans " ; and he has kindly satisfied me by occidar 

 demonstration and comparison that another fossil shell, 

 " Le Cardium Burdiyaliiium de Lamarck est une variete de 

 localite de la meme espece." 



The Cardium hians is of a light ventricose structure, 

 gaping widely at the posterior side, and the only species 

 approximating to that singularly formed shell the com- 

 mon Cardium costatum ; the ribs of this species are much 

 more feebly developed, but they exhibit a remarkable pe- 

 culiarity of sculpture, the anterior ribs being surmounted 

 with round vaulted scales somewhat bke those of a minia- 

 ture Tridacna, whilst the posterior, which are curiously 

 flattened down one against the other, are armed along the 

 edge with irregular short stout white spines, looking ex- 

 actly bke so many rows of small ivory tusks. 



Species 28. (Mus. Cuniing.) 

 Cardium imbricatum. Card, testa subquadrata, crassi- 

 usculd, antice rotundatd, postice angulatd, impresso- 

 concavd, radiatim costatd, costis angustis, elevatiusculis, 

 novenis et viginti, quarurn undecenis postremis parvis, 

 Iambus, cceteris squamis brevibus obesiusculis fornicatis 

 armatis ; extus uimi, iutus vivide aurantid, postice 

 purpurascente tinctd. 

 The imbricated Cockle. Shell somewhat square, rather 

 thick, rounded anteriorly, angulated, impressly con- 

 cave posteriorly, radiately ribbed, ribs narrow, rather 

 elevated, twenty nine in number, the eleven most pos- 

 terior of which are small, smooth, the rest armed 

 with short stout vaulted scales ; snowy white, interior 

 bright orange, stained on the posterior side with pale 

 purple. 

 Sowerby, Pro. Zool. Soc., 1810. 

 Ilab. Swan River Colony. 



The form of this shell is exactly similar to that of the 

 Cardium medium, the anterior and middle ribs being, how- 

 ever, much more strongly squaniiferous, and the interstices 

 more deeply furrowed. It is a solid characteristic shell 

 exhibiting, bke all specimens from the rich and abundant 

 locality above noted, an extremely deMcate contrast from 

 the interior, especially towards the hollow of the umbones, 

 being of a bright orange, tinged along the posterior edge 

 with pinkish purple, whilst the exterior is of a pure snowy 

 white. 



