CYPRICARDIA. 



Plate I. 



Genus Cypricardia, Lamarck. 



Testa tequivalvis , valde ineequilateralis, elongato-ovata, nun- 

 qiuim costata, latere antico brevissimo, postico sapis- 

 sim'e angulato. Cardo : dentibus tribus brevibus in- 

 fra umbonem utriusque valves, dente unico laterali, 

 elongato, interdum subobsoleto. Pallii. imprcssio mus- 

 cularis, leviter sinuosa. Ligamentum externum. 



Shell equivalve, very inequilateral, elongately ovate, 

 never ribbed, anterior side very short, posterior 

 most frequently angulated. Hinge : three short 

 teeth beneath the umbone of each valve, and a 

 single elongated lateral tooth, which is sometimes 

 nearly obsolete. Muscular impression of the mantle 

 slightly sinuous. Ligament external. 



The CypricardicB constitute one of the four genera in- 

 to which Lamarck distributed the Cardites of his prede- 

 cessor Bruguiere, and the propriety of that separation, as 

 respects the group under present consideration, has been 

 fully confirmed by subsequent discovery. The hinge of 

 Cypricardia is of much more complicated character than 

 that of Cardita, there being three short teeth beneath the 

 umbone, together with an elongated lateral tooth in 

 each valve : and the shell differs materially both in 

 structure and composition ; in structure, in being never 

 radiately ribbed ; in composition, in being of an opake 

 white nature, with little or no indication of an epi- 

 dermis. 



Of thirteen species now before me, only four of which 

 have ever been figured before, there are three, the C. co- 

 raUioplmga, decussata and laminata, which differ mate- 

 rially from the rest in their habits, inasmuch as they 

 live imbedded in shells, or large masses of madrepore, 

 after the manner of the Lithodomi, and, as regards the 

 shell, are not much unlike them in form and general 

 appearance. They are of a peculiar tenuity and trans- 

 parency, and do not present that posterior angulation 

 which is so prominent in the typical species. De Blain- 

 ville has already proposed to separate them under the 

 new generic title of Cora/liophaga, and it may yet be 

 matter for consideration whether this genus be not 

 worthy of adoption. 



Species 1. (Mus. Brit.) 

 Cypricardia lirata. Cypr. testa oblongo-ovatd, Icevi, 



albd; incrementi liris irregularibus, prominent ibus, 

 numerosis, ornatd, epidermide versus marginem in- 

 dutd ; umbonibus compressis ; inlus albd, postie'e vio- 

 laceo tinctd. 



The ridged Cypricardia. Shell oblong-ovate, smooth, 

 white, ornamented with numerous prominent irre- 

 gular ridges of growth, covered with an epidermis 

 towards the margin ; umbones compressed ; inte- 

 rior white, stained at the posterior end with violet. 



Reeve, Pro. Zool. Soc, 1843. 



Hab. ? 



The highly developed lateral tooth, so characteristic 

 in the typical species of this genus, is almost obso- 

 lete in this ; it differs from them also in the character 

 of the epidermis. 



Species 2. (Mus. Brit.) 



Cypricardia angulata. Cypr. testa subquadrato-ob- 

 longd, postie'e oblique angulata, decussatim striata, 

 striis longitudinalibus parallelis , latere postico oblique 

 truncato ; albidd, intus aurantio-luted , postie'e violaceo 

 vivide tinctd. 



The angulated Cypricardia. Shell somewhat square- 

 ly oblong, posteriorly obliquely angulated, decus- 

 sately striated, longitudinal stria; parallel to each 

 other, posterior side obliquely truncated ; whitish, 

 interior orange-yellow, vividly stained at the pos- 

 terior end with violet. 



Lamarck, Anim. sans vert. (Deshayes' edit.), vol. vi. 

 p. 438. 

 Chama oblonga, var., Chemnitz. 



Hab. ? 



The longitudinal striae of this species do not exhibit 

 that peculiar waved character which they present .n the 

 following ; it is a more solid shell, and much more 

 highly-coloured in the interior. 



Species 3. (Mus. Brit.) 



Cypricardia rostrata. Cypr. testa subquadrato-oblon- 

 gii, postice oblique angulntd, decussatim striatd, striis 

 longitudinalibus irregu/ariter undulatis; latere postico 

 productiore, subattenuato, rostrato ; albd, inlus albd, 

 postie'e violaceo leviter tinctd. 



September 1843. 



