Japanese sea biscuit; Clypeaster japonicus
A species of sand dollar found in Japanese waters. The name literally means 'octopus pillow', referring to its shape.
I found a Japanese sea biscuit shell on the beach.
The Japanese sea biscuit is a relative of sea urchins.
Katakana spelling is standard for this species name; usually written in kana.
Kanji spelling is rare and may not be widely recognized; the literal meaning is 'octopus pillow'.
Literally 'octopus pillow' (蛸の枕), from its resemblance to a pillow for an octopus. The exact origin of the name is uncertain.