The spines are removed from most of the surface of this sand dollar.

Sand Dollar

The spines are removed from most of the surface of this sand dollar.

"Encope emarginata. Encope is a genus of irregular clypeastroid sea-urchins, of the family Mellitidae." -Whitney, 1911

Encope

"Encope emarginata. Encope is a genus of irregular clypeastroid sea-urchins, of the family Mellitidae."…

Sea cucumber dissected to show alimentary canal.

Sea cucumber

Sea cucumber dissected to show alimentary canal.

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing…

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found…

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole of Archaeolcidaris; 3, A radiole of Cidaris; Jurassic; 4, Hemicidaris; Mid. Jurassic; 5, Salenia; Cretaceous; 6, Dyaster; Jurassic; 7, Enallaster; Cretaceous; 8, Catopygus; Cretaceous." -Britannica, 1910

Sea Urchin Fossils

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole…

A common form of star-fish.

Starfish

A common form of star-fish.

A fossil of Echinothuria floris, a species of sea urchin "having the plates of the shell overlapping or movably connected by soft parts." -Whitney, 1911

Urchin Fossil

A fossil of Echinothuria floris, a species of sea urchin "having the plates of the shell overlapping…

The Heart Urchin (Echinocardium cordatum) is sea urchin in the Loveniidae family.

Heart Urchin

The Heart Urchin (Echinocardium cordatum) is sea urchin in the Loveniidae family.

The Hawaiian Rock Urchin (Echinometra oblongata) is a sea urchin, here "with spines in part removed to show the plates of the test." -Whitney, 1911

Hawaiian Rock Urchin

The Hawaiian Rock Urchin (Echinometra oblongata) is a sea urchin, here "with spines in part removed…

Sea urchin: the heavy projections are the spines; the long, slender ones are the tube feet.

Sea Urchin

Sea urchin: the heavy projections are the spines; the long, slender ones are the tube feet.

Phormosoma luculentum is a species of Sea Urchin in the class Echinoidea.

Sea Urchin

Phormosoma luculentum is a species of Sea Urchin in the class Echinoidea.