C A R D I U M. 



Plate VI. 



Species 29. (Mus. Saul.) 



Cardium biangulatum. Card, testa subquadrato-cor- 

 datd, antice rotundatd, postice concavo-angulatd, sub- 

 productd, radiatim costatd, costis octonis et viginti, 

 quorum novenis postremh angustis,parvis, rotundis, ce- 

 teris latioribus, planiusculis, peculiariter obliquo- seu 

 undato-crenatis, costarum interstitiis transversim ele- 

 vaio-striatk ; intus vivide purpurea. 



The double-angled Cockle. Shell somewhat squarely 

 cordate, rounded anteriorly, concavely angulated and 

 a little produced posteriorly, radiatelj ribbed, ribs 

 twenty-eight in number, tie extreme posterior nine 

 of which are narrow, small, round, the rest wider, ra- 

 ttier flat and peculiarly obliquely or undately crenated, 

 interstices between the ribs transversely elevately cre- 

 nated ; interior richly stained with purple. 



Sowerby, Zool. Journal, vol. iv. p. 307 ; Conch. Illus. f.2. 



Hah. St. Elena and Isle of Plata, West Columbia (found 

 in coral sand at the depth of seventeen fathoms) ; 

 Cuming. 

 A species well distinguished amongst other characters 



by the peculiarly irregular manner in which the ribs are 



crenated, and by its rich purple interior. 



Species 30. (Mus. Cuming.) 

 Cardium medium. Card, testa subquadrato-cordatd, an- 

 tice rotundatd, postice concavo-angulatd, radiatim cos- 

 tatd, costis senis et triginta, angustis, anticis brevisqua- 

 mosis ; albidd, rubido-fusco nebulosd et maculatd ; in- 

 tus albd. 

 The middle Cockle. Shell somewhat squarely cordate, 

 rounded anteriorly, concavely angulated posteriorly, 

 radiately ribbed, ribs six and thirty in number, nar- 

 row, the anterior covered with short scales; whitish, 

 clouded and spotted with reddish brown; interior 

 white. 

 Linn.eus, Syst. Nat., p. 1121. 



Hob. Islands of Nevis and St. Vincent, West Indies (found 

 in sandy mud at the depth of about six fathoms) ; 

 Guilding. 

 It is a curious circumstance in the structure of this shell 

 that the three most extreme posterior ribs next the liga- 

 ment arc broader than any of the rest. 



Species 31. (Mus. Cuming.) 



Cardium planicostati m. Card, testa subquadrato-cor- 

 datd, umbones versus attenuald, unlU-i- roluudold, pos- 

 tice brevissime concavo-angulatd, area postica medio 

 prominulo, radiatim costatd, costis tricenis, plants, acu- 

 timarginatis, anticis subrugoso-crenatis, posticis postici 

 subtiliter serratis, omnibus striis impressis arcuatis ere- 

 benime exsculptis ; costarum interstitiis profundi ex- 

 cavatis ; rufescenU -earned, fusco m-buluad et maculatd, 

 intus olid. 



The fl.vt-ribised Cockle. Shell somewhat squarelj 

 cordate, attenuated towards the umbones, rounded 

 anteriorly, very short, concavely angulated posteriorly, 

 middle of the posterior area prominent, radiately 

 ribbed, ribs thirty in number, flat, sharp-edged, the 

 anterior crenated in a somewhat wrinkled manner, 

 posterior finely seriated along the posterior edge, the 

 whole very closely sculptured with arched impressed 

 striie; interstices between the ribs deeply excavated: 

 warm pinkish flesh-colour, clouded and spotted with 

 brown ; interior white. 



Sowerby, Pro. Zool. Soc, 1S33 ; Conch. Illus., f. 25. 



llah. Guacomayo, Central America (found in tine sand at 

 the depth of thirteen fathoms); Cuming. 



One of the most remarkable features in this species is 

 the extremely delicate manner in which the flattened sur- 

 face of the ribs is verj minutely engraved throughout with 

 close-set arched impressed striae. The specimen here 

 figured, from the collection of Mr. Cuming, and one in the 

 British Museum, are all that have as yet been discovered. 



Species 32. ( Mus. Cuming.) 



Cardium muticum. Card, testa transverse ovatd, de- 

 pressd, tenui, fragili, antice paulo hiante, undique mu- 

 ticd, radiatim impresso-striatd, slriis rudo-incisis, mi- 



nutissill/i' uuduloli.s, r/iidrrmiilr tritlii roi/ioo ut'ihus, 



st riorum lateralium interstitiis medio concavis ; lutes- 

 cente, ru.sari-o-/iur/iuiwirn/c umbones versus pallide 

 tinctd. 

 The smooth Cockle, shell transverselj ovate, depressed, 

 thin, fragile, a little gaping anteriorly, everywhere 

 smooth, radiatelj impresslj striated, striae rudely en- 

 graved, ur\ minutelj waved or zigzag, giving root 



November Is 1 I. 



