Lamarck took this genus from the Chama on account of several
peculiarities in the shell as well as in the animal. It is not affixed
to other bodies by its lower valve, but, according to De Blainville,
lies exposed on the rocks. There is some difficulty in distinguishing
this genus from the Venericardia, without carefully examining the
position of the two teeth.
Shell regular, thick, solid, equivalve, more or less inequilateral;
summit dorsal, always very recurved anteriorly; hinge similar, formed by
two oblique teeth; one short cardinal placed beneath the umbo, the other
oblique, arched, marginal, and prolonged; ligament elongated,
sub-exterior, and inserted; two very distinct muscular impressions.
Cardita sulcata.
C. ajar.
C. turgida.
C. squamosa.
C. phrenetica.
C. crassicosta.
C. rufescens.
C. calyculata.
C. subaspera.
C. nodulosa.
C. intermedia.
C. trepezia.
C. bicolor.
C. depressa.
C. concamerata.
C. sinuata.
C. aviculina.
C. citrina.
C. sublævigata.
C. corbularis.
C. lithophagella.
_C. crassicosta._ The thick-ribbed Cardita.
Species elongated, a little gaping at the inferior margin; ligament
concealed.
_C. sulcata._ The furrowed Cardita. Pl. 10, fig. 3.
Sub-cordiform or oval, more transverse than longitudinal; colour white,
tesselated with brown; posterior depression heart-shaped; longitudinal,
convex, transversely-striated ribs.