Convex Slipper Shell
The Convex Slipper Shell is highly arched. The deck, plate, partition, shelf, or septum (lots of names for the internal platform) of Crepidula convexa is deeply inset. The exterior of the shell is dark reddish- or purplish-brown with slight wrinkles on the surface. Colors, however, may vary — the shell could be worn, weathered, fossilized, or discolored from having been in sediment containing organic matter, or chemicals which altered the shell's natural coloration. The shell may be thick and sturdy, or rather fragile. (Usually the fragile ones are attached to another shell.)
The shell is shaped like an elongated oval with a conspicuous “snout,” or apex, that twists to one side and turns down almost to the plane of the shell's aperture, or opening. In fact, sometimes the apex even curves down below the edge of the aperture. The gastropod shell looks something like a very deeply dug-out canoe (shells from this family are often called Boat Shells). It may be found from Massachusetts to the West Indies and Texas; on Bermuda shores; and on the coast of California. The living creature is a resident of shallow water.