The ornamental design for a finial, as shown and described.
FIG. 1 is a perspective view from below of a finial in accordance with my design;
FIG. 2 is an enlarged perspective view from below of the finial in accordance with my design;
FIG. 3 is an enlarged front elevation view of the finial in accordance with my design;
FIG. 4 is an enlarged back elevation view of the finial in accordance with my design;
FIG. 5 is an enlarged bottom plan view of the finial in accordance with my design; and,
FIG. 6 is an enlarged side elevation view of the finial in accordance with my design, the opposite view being a mirror image of that shown.
The broken line showing of the support rod, fan blades, fan blade ornamentation, motor housing, light fixture and blade irons is included for the purpose of illustrating environmental structure and forms no part of the claimed design.