The Collaborative International Dictionary of English v.0.48:

Leontocebus \Leontocebus\ prop. n.
   A genus of marmosets including some of the tamarins. Called
   also Leontopithecus and Leontideus.

   Syn: genus Leontocebus, genus Leontideus, genus
        Leontopithecus.
        [WordNet 1.5]