The ornamental design for a finial, as shown and described.
FIG. 1 is a bottom perspective view of a ceiling fan motor housing showing my new design in use;
FIG. 2 is an enlarged bottom perspective view of the finial in accordance with my design;
FIG. 3 is an enlarged side elevation view of the finial in accordance with my design, all sides being substantially identical; and,
FIG. 4 is an enlarged bottom plan view of the finial in accordance with my design.
The broken line showing of the ceiling fan is included for the purpose of illustrating environmental structure and forms no part of the claimed design.