The Collaborative International Dictionary of English v.0.48:

Rhombogene \Rhom"bo*gene\ (r[o^]m"b[-o]*j[=e]n), n. [Rhomb +
   root of Gr. gi`gnesqai to be born.] (Zool.)
   A dicyemid which produces infusorialike embryos; -- opposed
   to nematogene. See Dicyemata. [Written also rhombogen.]
   [1913 Webster]