  The masses of experimentally known highly excited baryons of negative parity
supposed to belong to the $[{\bf 70},\ell^-]$ multiplets ($\ell$ = 1,2,3) of
the $N = 3$ band are calculated in the $1/N_c$ expansion method to order
$1/N_c$ by using a procedure which allows to considerably reduce the number of
linearly independent operators entering the mass formula. The numerical fits to
present data show that the coefficients encoding the QCD dynamics have large,
comparable values, for the flavor and spin operators. It implies that these
operators contribute dominantly to the flavor-spin SU(6) symmetry breaking,
like for the $[{\bf 70},1^-]$ multiplet of the $N = 1$ band.
