  From measurements of the magnetic penetration depth, $\lambda(T)$, from 1.6 K
to $T_c$ in films of electron-doped cuprates La$_{2-x}$Ce$_x$CuO$_{4-y}$ and
Pr$_{2-x}$Ce$_x$CuO$_{4-y}$ we obtain the normalized density of states,
$N_s(E)$ at T=0 by using a simple model. In this framework, the flat behavior
of $\lambda^{-2}(T)$ at low $T$ implies $N_s(E)$ is small, possibly gapped, at
low energies. The upward curvature in $\lambda^{-2}(T)$ near $T_c$ seen in
overdoped films implies that superfluid comes from an anomalously small energy
band within about $3k_BT_c$ of the Fermi surface.
