DRAGON-SHELL, noun A species of concamerated patella or limpet. The top is much curved, and of an ash-color on the outside, but internally, of a bright flesh color. It is found adhering to larger shells, or to the back of the tortoise, as common limpets do to the sides of rocks.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI