When Linnæus formed this genus and named it Anomia, he probably did so
from its having no determinate character. Its common name was given it
by the fancied resemblance of some of its species to an antique lamp.
Like the oyster, they seldom leave their place; they are always affixed
to marine bodies by an osseous operculum, formed by the thick extremity
of the animal’s muscle. The lower valve is perforated and smaller,
conforming to the shape of the substance to which it is affixed.
Shell adhering, irregular, inequivalve, inequilateral, ostraceous;
inferior valve rather more flat than the superior, divided at the summit
into two sloping branches, whose approaching together forms a large oval
hole, through which protrudes a muscle, the extremity of which becomes
ossified and adheres to extraneous bodies; one sub-central muscular
impression divided into three.
Anomia ephippium.
A. patellaris.
A. cepa.
A. electrica.
A. pyriformis.
A. fornicata.
A. membranacea.
A. squamula.
A. lens.
_A. ephippium._ The Saddle Anomia. Pl. 16, fig. 1.
Shell sub-orbicular, irregularly wrinkled and waved; upper valve convex,
under flat and perforated at the hinge, through which passes the
ligament by which it is affixed to other bodies; inside pearly, and of
various changing colours, such as green, purple, violet, and yellow.