Comparison of theoretical (empty symbols) to observed (filled symbols) period spacing for the primary (top panels) and the secondary (bottom panels). Ledoux splitting has been applied to the theoretical zonal modes to fit the retrograde and prograde modes. The uncertainties of the observed period spacings are smaller than the symbols. The radial orders k are indicated near selected modes. Dipole modes of radial order −31 ≤ k ≤ −20 are shown for the primary and −37 ≤ k ≤ −25 for the secondary, while the radial orders of the quadrupole modes are −28 ≤ k ≤ −35 and −29 ≤ k ≤ −36, respectively.