The Collaborative International Dictionary of English v.0.48:

Notornis \No*tor"nis\, prop. n. [NL., fr. Gr. no`tos the south,
   or southwest + ? bird.] (Zool.)
   A genus of birds allied to the gallinules, but having
   rudimentary wings and incapable of flight. Notornis
   Mantelli was first known as a fossil bird of New Zealand,
   but subsequently a few individuals were found living on the
   southern island. It is supposed to be now nearly or quite
   extinct.
   [1913 Webster]

WordNet (r) 3.0 (2006):

notornis
    n 1: flightless New Zealand birds similar to gallinules [syn:
         notornis, takahe, Notornis mantelli]