noun
Japanese sea biscuit; Clypeaster japonicus
A species of sand dollar found in Japanese waters. The name literally means 'octopus pillow', referring to its shape.
海岸でタコノマクラの殻を見つけた。
I found a Japanese sea biscuit shell on the beach.
タコノマクラはウニの仲間だ。
The Japanese sea biscuit is a relative of sea urchins.
Literally 'octopus pillow' (蛸の枕), from its resemblance to a pillow for an octopus. The exact origin of the name is uncertain.