Atlantic Horseshoe Crab carapace eye (Limulus polyphemus)

The Atlantic horseshoe crab, "Limulus polyphemus", is a marine chelicerate arthropod. Despite its name, it is more closely related to spiders, ticks, and scorpions than to crabs. Horseshoe crabs are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America. A main area of annual migration is Delaware Bay, although stray individuals are occasionally found in Europe.

The other three species in the family Limulidae are also called horseshoe crabs....hieroglyph.. more