Pallial

a.
  1. Of or pertaining to a mantle, especially to the mantle of mollusks; produced by the mantle; as, the pallial line, or impression, which marks the attachment of the mantle on the inner surface of a bivalve shell. See Illust. of Bivalve.
    2. Pallial chamber (Zoöl.),
    the cavity inclosed by the mantle.
    Pallial sinus (Zoöl.),
    an inward bending of the pallial line, near the posterior end of certain bivalve shells, to receive the siphon. See Illust. of Bivalve.