Dictionary
horse'shoe crab'
a large marine arthropod,
Limulus polyphemus, of shallow coastal waters of eastern North America and eastern Asia, having both compound and simple eyes, book gills, a stiff tail, and a brown carapace curved like a horseshoe: a living fossil related to the woodlouse. Also called
king crab. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.