  We investigate the mass spectra of closed-charm mesons with $ J^{PC} = 1^{--}
$, for hybrid charmonium, molecules, and diquark-antidiquark operators, in
quenched lattice QCD with exact chiral symmetry. For two lattice volumes $ 24^3
\times 48 $ and $ 20^3 \times 40 $, each of 100 gauge configurations generated
with single-plaquette action at $ \beta = 6.1 $, we compute point-to-point
quark propagators and measure the time-correlation functions of these exotic
meson operators. For the molecular operator $
\{(\qbar\gamma_5\gamma_i\c)(\cbar\gamma_5\q)-
  (\cbar\gamma_5\gamma_i\q)(\qbar\gamma_5\c) \} $, it detects a resonance with
mass around $ 4238 \pm 31 $ MeV, which is naturally identified with $ Y(4260)
$. Further, for any molecular and diquark-antidiquark operator, it detects
heavier exotic charmed mesons, with quark content $ (\c\s\cbar\sbar) $ around $
4450 \pm 100 $ MeV, and $ (\c\c\cbar\cbar) $ around $ 6400 \pm 50 $ MeV.
