From The Collaborative International Dictionary of English v.0.48 :
Perdix \Per"dix\ (p[~e]r"d[i^]ks), prop. n. [L., a partridge,
Gr. pe`rdix.] (Zool.)
A genus of birds including the common European partridge.
Formerly the word was used in a much wider sense to include
many allied genera.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
Perdix
n 1: a genus of Perdicinae [syn: Perdix, genus Perdix]