acrolith

from The Century Dictionary.

• noun In Greek antiquity, a sculptured figure of which only the head and extremities were carved in stone, the rest being generally of wood, and covered with either textile drapery or thin plates of metal.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Arch. & Sculp.) A statue whose extremities are of stone, the trunk being generally of wood.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An ancient Greek wooden statue with limbs and head of stone.