Hello Linda,

You are right on both counts - razor clams, like all bivalves, are filter
feeders.  And they typically live buried in sand or mud, with just the
anterior tip of the shell extending above the surface of the sediment, or
sometimes completely buried.  Ensis and Solen are true razor clams (also
called jackknife clams), in the family Solenidae.  Pharus, though it is long
and slender, is a member of a different family, Solecurtidae, which also
includes such genera as Solecurtus, Tagelus, Azorinus, etc.  Razor clams are
rapid burrowers.  More than one collector, after having dug a number of
specimens out of the mud, has dumped them out of the bucket in shallow
water, to wash them off, only to have them all disapper into the mud again
before they could be re-collected.  Their digging action can also pull them
through the water, so they can actually swim fairly rapidly for a short
distance.  Ensis and Solen are edible, but not commonly offered on the
commercial marketplace.

Paul M.