||E*chi`no*coc"cus (?), n. [NL., fr.
Gr. ? hedgehog, sea urchin + ? grain, seed. So called because
forming little granular bodies, each armed with hooklets and disposed
upon the inner wall of the hydatid cysts.] (Zoöl.) A
parasite of man and of many domestic and wild animals, forming
compound cysts or tumors (called hydatid cysts) in various organs,
but especially in the liver and lungs, which often cause death. It is
the larval stage of the Tænia echinococcus, a small
tapeworm peculiar to the dog.