Limulus \Lim"u*lus\ (l[i^]m"[-u]*l[u^]s), n.; pl. {Limuli} (-l[imac]). [L., dim. of limus sidelong, askance.] (Zo["o]l.) The only existing genus of Merostomata. It includes only a few species from the East Indies, and one ({Limulus polyphemus}) from the Atlantic coast of North America. Called also {Molucca crab}, {king crab}, {horseshoe crab}, and {horsefoot}.