  Present data on neutrino masses and mixing favor the highly symmetric
tribimaximal neutrino mixing matrix which suggests an underlying flavor
symmetry. A systematic study of non-abelian finite groups of order $g \leq 31$
reveals that tribimaximal mixing can be derived not only from the well known
tetrahedral flavor symmetry $T \equiv A_4$, but also by using the binary
tetrahedral symmetry $T^{'} \equiv SL_2(F_3)$ which does not contain the
tetrahedral group as a subgroup. $T^{'}$ has the further advantage that it can
also neatly accommodate the quark masses including a heavy top quark.
