The Collaborative International Dictionary of English v.0.48:

Ditokous \Di"to*kous\, a. [Gr. di- = di`s- twice + ? a bringing
   forth, offspring.] (Zool.)
   (a) Having two kinds of young, as certain annelids.
   (b) Producing only two eggs for a clutch, as certain birds
       do.
       [1913 Webster]