In the USA, other common names for species in this genus are razor clams or jackknife clams. This is because the long, narrow, and parallel-sided shape of their shells is unusual in bivalves. The shape of these clams resembles a closed, old-fashioned straight razor (a cut-throat razor), or a closed jackknife (pocket knife). The shells are fragile and can easily be damaged when digging for these clams.
Ensis species live in clean sand on exposed beaches. They are capable of digging very rapidly; see the description under the Atlantic jackknife clam.