coenurus
Coe*nu"rus, n. Etym: [NL. fr. Gr. (Zoöl.) Defn: The larval stage of a tapeworm (Tænia coenurus) which forms bladderlike sacs in the brain of sheep, causing the fatal disease known as water brain, vertigo, staggers or gid. Note: This bladder worm has on its surface numerous small heads, each of which, when swallowed by a dog, becomes a mature tapeworm in the dog's intestine.