xiphosurus polyphemus(n = noun.animal) horseshoe crab, king crab, limulus 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, limulus polyphemus, polyphemus, polyphemus moth