PSAMMOBIA VESPERTINA..indicates, in sand covered by the sea, from the water's edge to great depths. They are said to be active in their motions, burrowing with rapidity and ease in the sandy bed of the sea. We have several British species, one of the most elegant of which is sometimes called by collectors the Setting Sun (Psammobia vespertina), from its warm pink hue, and the pale bands which radiate from the beaks to all parts of the margin, like the rays which frequently stretch across the sky from the evening horizon. This species is commonly about two inches in breadth, and is not at all uncommon, burrowing beneath the surface near low-water mark on most of our sandy beaches, where the detached valves washed on shore by the tides are often picked up, and always admired.
Every one who has paced along the water's edge on a sandy beach, is familiar with the shells which form the type of this family. Their extreme narrowness and length, (or, to speak strictly, shortness and breadth,) their parallel sides and truncate