From The Collaborative International Dictionary of English v.0.48:
Notodontian \No`to*don"tian\, n. [Gr. nw^ton the back + 'odoy`s,
'odo`ntos a tooth.] (Zool.)
Any one of several species of bombycid moths belonging to
Notodonta, Nerice, and allied genera. The caterpillar of
these moths has a hump, or spine, on its back.