Rock Crab (_Cancer irroratus_): A brick-red shell, somewhat granulated, with a black and yellowish undersurface. Jonah Crab (_Cancer borealis_): Similar in color to the above, but its shell has a more sculptured surface. Green Crab (_Carcinides maenas_): A greenish-colored shell. The last pair of legs end in sharp points, rather than being flattened like paddles. [Illustration: Horseshoe Crab] Horseshoe Crab (_Limulus polyphemus_) Shell with horseshoe-shaped outline Long, sharply pointed tail Two immovable compound eyes The Horseshoe is not a Crab at all, but is more closely related to the spiders, mites, and scorpions. In spite of its relations, the Horseshoe is a harmless creature whose only protection is its hard shell. Therefore it may be examined freely—a strange “living fossil” that has survived 400,000,000 years of evolution with very little change. _The Mollusks_ [Illustration: Oyster] Oyster (_Ostrea virginica_) Mottled, unattractive shell Gray splotches on inside surface Even without pearls, our Oyster is worth many thousands of dollars a year to shellfish dealers because of its delicious flesh. Its tropical relatives are the pearl producers. [Illustration: Mussels] Mussels (_Mytilidae_) Blue-colored shells Shells covered with black, horny skin Living mussels are always found attached to rocks or pieces of wood by tiny threads of their own making. Two common mussels are: Edible Mussel (_Mytilus edulis_): Smooth, velvety-blue shell identifies it. The animal within is edible and quite delicious. It is commonly utilized as food in Europe but less so here, where we have, and seem to prefer, the Oyster. Ribbed Mussel (_Modiolus demissus plicatulus_): Similar to the above but with many distinct ribs radiating on the surface. The Ribbed Mussel is not considered edible. While not poisonous, it is most unpalatable. [Illustration: Hardshell Clam] Hardshell Clam (_Venus mercenaria_) Thick, round shell Purple blotches on inside surface Also called “Quahog,” “Little Neck,” “Round Clam,” or “Cherrystone,” the Hardshell Clam is another highly prized seafood. [Illustration: Edible Clam] Edible Clam (_Mya arenaria_) Fragile shell with egg-shaped outline Wing extending out from inside top of left half of shell These clams are found just a foot or so under the sand, and their empty shells are common on the beaches. This is the Softshell Clam, which we enjoy steamed, baked, or fried, as well as in New England’s famous clambakes and clam chowders. [Illustration: Surf Clam] Surf Clam (_Spisula solidissima_) Very large shell Spoon-shaped trough at inside top of shell This is the largest clam on the Atlantic seaboard, growing up to about seven inches in length. It is edible, and just one or two make a large chowder. The shell makes a fine ashtray and an unusual and useful souvenir.