Always without accessory pieces, and, therefore, easily distinguished
from the Pholas.
Shell equivalve, somewhat wedge-shaped, with a very large, oval,
oblique, anterior opening between the valves; the posterior extremity
nearly close; hinge linear, marginal, without teeth; two distant
muscular impressions; sometimes with a kind of tube or calcareous
general envelope.
Gastrochæna cuneiformis.
G. mytiloides.
G. modiolina.
_G. modiolina._ The Modioliform Gastrochæna.
Oval, thin, brittle, gaping at the side; light reddish brown, with a
bluish white interior.
_G. cuneiformis._ The wedgelike Gastrochæna. Pl. 3, fig. 1.
Species with a smooth shell, and without distinct tube. (Represented as
imbedded in wood.)
FAMILY III.
SOLENIDES. Four genera.