Mollusca in the Collection of the Zoological Society, 367 



We have seen only one specimen. The surfaces of the anterior ribs 

 as well as the interstices are covered with minute raised dots, and a slen- 

 der horny fringe of epidermis is observable on the posterior edges of the 

 hinder ridges. The marginal teeth are large, and deeply cut. In Mr. 

 Bland's collection. 



CaRDIUM DiONiEUM. 



C testd cordatd, valvis convexis, carinatis, carind dentatd, costis ra,' 

 diantlhus suhlcevihus, anticis suhgranosis^ duabus posticis siibser- 

 ratis ; long. 1, lat. lyV* «^<- 1 iVj P^l^- 

 Hah, in Oceano Pacifico. 



Several specimens of this elegant Cardium, in different stages of 

 growth, were collected by Lieut. Belcher. In the young specimens the 

 anterior side is more prominent tiian the posterior ; the teeth on the keel 

 also are more distinct and pointed than in the full grown specimens, until 

 they become entirely obsolete in the aged specimens. The largest indi- 

 vidual we have seen is in the Cabinet of Mr. Bland ; it is white, inclin- 

 ing to orange colour towards the edges, which are much more obtuse 

 than in the younger specimens. From an Island in the Southern Pacific 

 Ocean. 



Cardium qraniferum. 



C testd suborhiculari, postice angulatd, costis radiantibus 16 grani- 

 feris, posticis confertis ; interstitiis longitudinaliter concinnh stri- 

 atis; long, 3-%, lat yV^ «^^' H> polL 

 Hob. ad littora Oceani Pacifici. 



A beautiful small white Cardium, with distant and very prominent 

 ridges, and numerous grains set on their edges ; these grains are larger 

 on the anterior than on the posterior ridges. Dug from a depth of about 

 6 inches in the mud of the Estaro de Mazatlan. 



Cardium biangulatum. 



C. testd turgidd, oblique subcordatd, antice rotandatd, postich biangu- 

 latd ; costis radiantibus longitudinaliter striatis, anticis subcre- 

 natiSf posticis rugulosis ; interstitiis punctatis ; long. -jS^, lat. y^^, 

 alt. -y\, poll. 

 Hab. 



BB 2 



