Pacific sand dollar

Description:

Disc about 4" across, about 1/2" high. These are best known by the shell they leave behind when they die, but when alive the shell is covered by dark velvet.

Habitat:

Pacific bay, cool waters.

Notes:

These were spotted in the Oregon Aquarium, but they can be found east of the Alsea Bay bridge in the bay there, in fairly shallow water that's uncovered by tides occasionally.