The Collaborative International Dictionary of English v.0.48:

Gerbillus \Gerbillus\ n.
   The type genus of the Gerbillinae, comprising the typical
   gerbils[1].

   Syn: genus Gerbillus.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Gerbillus
    n 1: type genus of the Gerbillinae: typical gerbils [syn:
         Gerbillus, genus Gerbillus]