Solid shell up to about 15cm in length. It is quite variable in appearance (possibly party due to growing in different salinities). The outside is dirty white to fawn in colur; the inside is white. The surface of the shell is sculptured with concentric rings and a few radiating lines. The right valve is slightly larger than the left and the shells gape at the hind end.
- Large 'spoon' shaped chondrophore in the left valve and concealed chondrophore in the right valve
- Lower margin of pallial line is not confluent with pallial sinus
Burrows in sand, mud or sandy gravel to a depth of up to 30cm where it feeds by filtering phytoplankton. It can tolerate reduced salinity and so is often found in estuaries.