The only living species of this genus is found on the sand in
New-Holland, but there are many fossils in France. It is so equivocal in
character that it is difficult to judge of their hinge.
_E. cardioides._ The cardium-shaped Erycina. Pl. 6, fig. 5.
Shell rather longer than high, sub-triangular, regular, equivalve,
inequilateral, rarely gaping; the summits well marked and a little
anteriorly inclined; hinge subsimilar; two unequal cardinal teeth,
converging at the summit, and leaving a pit between them; two lateral
teeth, not distant, lamellous, inserted; ligament interior, fixed in the
cavity between the primary teeth.