  The data for 9.3 million Upsilon(2S) and 20.9 million Upsilon(1S) taken with
the CLEO III detector has been used to study the radiative population of states
identified by their decay into twenty six different exclusive hadronic final
states. In the Upsilon(2S) decays an enhancement is observed at a ~5 sigma
level at a mass of 9974.6+-2.3(stat)+-2.1(syst) MeV. It is attributed to
eta_b(2S), and corresponds to the Upsilon(2S) hyperfine splitting of
48.7+-2.3(stat)+-2.1(syst) MeV. In the Upsilon(1S) decays, the identification
of eta_b(1S) is confirmed at a ~3 sigma level with M(eta_b(1S)) in agreement
with its known value.
