This term is derived from the Greek word μυω, to close, alluding to the
animal’s custom of closing the valves. The principal characteristic of
the Mya is its gaping at one end; it is likewise distinguished by having
a large spoonlike tooth proceeding from beneath the beak. Its form is
greatly varied, but generally covered with a greenish epidermis, which
may be removed; and the shell, when polished, will display beautiful
prismatic colours. The Mya is found on the seashore or on the banks of
large rivers, partially concealed in the sand and mud.
Shell transverse, inequilateral, surrounded with a thick epidermis;
rather solid; edges thin and sharp; summits but little marked; hinge
dissimilar; one or two large, compressed, spoon-shaped teeth rising
perpendicularly from the plane of the left valve, and fitting into the
entrance of a primary cavity in the right valve; ligament interior,
attaching the tooth and cavity; two distant muscular impressions; the
anterior long and narrow, the posterior rounded; the mantle impression
narrow, with a large sinus or hollow.
Mya truncata.
M. arenaria.
M. erodona.
M. solenimyalis.
_M. arenaria._ The Sand Mya. Pl. 5, fig. 1.
Regular species.
_M. erodona._ The Erodona Mya.
Irregular species, in which the cavity of the right valve is bordered by
strong projections.
_M. truncata._ The truncated Mya. Pl. 5, fig. 3.
Sub-oval, truncated; small end gaping; large end rounded; covered with a
dark yellowish epidermis; inside white; wrinkled transversely.