limulus polyphemus(n = noun.animal) horseshoe crab, king crab, xiphosurus polyphemus - large marine arthropod of the Atlantic coast of North America having a domed carapace that is shaped like a horseshoe and a stiff pointed tail; a living fossil related to the wood louse;
is a kind of arthropod
is a member of genus limulus, limulus

antheraea polyphemus, genus limulus, limulus, polyphemus, polyphemus moth, xiphosurus polyphemus