Mollnsca in the Collection of the Zoological Society. 36/ 



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 Dion^um. 



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

 diantibus sublcevibns, anticis subgranosis, duabus posticis sii.bser- 

 ratis ; long. 1, kit. lyV» «'^- l^rV» T'"//. 

 Hob. in Oceano Pacifico. 



Several specimens of this elegant Cardium, m different stages of 

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

 anterior side is more prominent than 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 oransfe colour towards the edges, which are much more obtuse 

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

 Ocean. 



Cardium graniferum. 



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

 ferisy posticis confertis ; interstitiis longitadinaliter concinne stri- 

 atis; long. ^%, lat. f*^, alt. \^, 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 tiirgidd, oblique subcordatd, antice rotundatd, postich biahgu- 



latd ; costis radiantibus longitadinaliter striatis, anticis snbcre- 



natis, posticis rugulosis ; interstitiis punctatis ; long. -^^, lat. -^^, 



alt. -y\, poll. 



Hab. 



BB 2 



