CARDITA. 



Plate VII. 



Species 31. (Mus. Cuming.) 



irdita lacunosa. Card, testa Sttbovatd, radiatim cos- 

 tatd, costis una vel duabus et viginti, elevatis, vald'e 

 compressis, subtiliter muricato-squamosis ; interstitiis 

 latiusculis, lacunato-excavatis ; alba, area posticali 

 nigerrimo-fuscd. 



se guttered Cardita. Shell somewhat oval, ra- 

 diately ribbed, ribs one or two and twenty in num- 

 ber, elevated, very narrow and compressed, sur- 

 mounted with fine prickly scales; interstices between 

 the ribs rather wide, and excavated like gutters, as 

 it were; white, posterior area of the shell blackish - 

 brown. 



eeve, Pro. Zool. Soc, 1843. 



ab. ? 



The prickly scales which surmount the singularly 

 impressed ribs of this shell are placed at equal distances 

 Dm each other, whilst each rib is in a manner festooned 

 Dm one scale to the other, like a miniature series of in- 

 :rted arches. 



Species 32. (Mus. Cuming.) 



ardita spurca. Card, testd ovatd, vel oblongo-ovatd. 

 gibbosd, albidd, epidermide olivaced, umbones versus 

 plus minusve decorticatd, indutd; radiatim costatd, 

 costis octodecim, eminentibus, nodulosis ; latere pos- 

 tico super lie subangulato. 



he dirty Cardita. Shell ovate or oblong-ovate, gib- 

 bous, whitish, covered with a dirty olivaceous epi- 

 dermis, more or less decorticated towards the um- 

 bones ; radiately ribbed, ribs eighteen in number, 

 strongly developed, nodulous ; posterior side of the 

 shell slightly angulated. 



owerby, Pro. Zool. Soc, 1832. 



Jab. Iquiqui, Coast of Peru (dredged from coarse sand 

 and gravel at the depth of from six to ten fathoms) . 



This species varies considerably in form, some speci- 

 lens being so much more oblong than others ; and the 

 bs in like manner are broader or more spread. 



Species 33. (Mus. Metcalfe.) 



ardita borealis. Card, testd suborbiculari, depres- 

 siusculd, albidd, epidermide crassd, olivaced, umbones 



versus paululum decorticatd, indutd; radiatim cos- 

 tatd, costis octodecim, nunc angustis, compressis, nunc 

 depresso-convexis, rugosis vel obsolete nodulosis. 



The northern Cardita. Shell nearly orbicular, rather 

 depressed, whitish, covered with a thick olivaceous 

 epidermis a little decorticated towards the umbones ; 

 radiately ribbed, ribs eighteen in number, sometimes 

 narrow and compressed, sometimes depressly con- 

 vex and spread, wrinkled or obsoletely nodulous. 

 Venericardia borealis, Conrad, Amer. Mar. Conch., 

 No. 3. pi. 8. f. 1. 



Hab. Coast of Massachusetts, North America (found by 

 Dr. Pickering) ; Conrad. 



The Carditee spurca and borealis seem to present re- 

 markable modifications of the same characters, and if a 

 more extended series of specimens should prove them to 

 be varieties of one and the same species, Conrad's name 

 should be preserved, as having the priority of a few 

 months over that of Mr. Sowerby. I publish the two 

 species as I find them, as I cannot verify my suspicions. 

 The Cardita borealis may be described as being rounder 

 and more depressed than the C. spurca, whilst the ribs 

 present but little indication of being nodulous. 



Species 34. (Mus. Cuming.) 



Cardita crassa. Card, testd subquadrato-ovali, gibbo- 

 sissimd, antic'e brevissimd ; albd, maculis rubido-fus- 

 cis perpaucis prope umbones ornutd, epidermide luteo- 

 fuscd indutd ; radiatim costatd, costis rotundis, lati- 

 usculis, umbones versus subti/issimi- geniculatis, late- 

 ribus hie et illic indistinc/i serratis, interstitiis per- 

 angustis; intus alba, margins irregulariter undulato. 



The thick Cardita. Shell somewhat squarely oval, 

 extremely gibbous, anteriorly very short ; white, 

 ornamented with a few scattered reddish-brown 

 spots near the umbones, and covered with a yel- 

 lowish-brown epidermis ; radiately ribbed, ribs 

 round, rather broad, and very finely geniculated 

 towards the umbones, sides of the ribs here and 

 there indistinctly seriated, interstices between the 

 ribs very narrow ; interior of the shell white, mar- 

 gin irregularly undulated. 



Gray, Zool. Eeechey's Voy., p. 152. pi. 42. f. 4. 



Hab. Acapulco ; Beechey. 



The Cardita crassa is remarkable for its very gibbous 



August 1843. 



