What is claimed is the ornamental design for a bookmark, as shown and described.
FIG. 1 is a perspective view of a bookmark, showing the new design;
FIG. 2 is a front elevational view thereof, a loop portion thereof partially omitted for clarity of illustration;
FIG. 3 is a rear elevational view thereof, a loop portion thereof partially omitted for clarity of illustration;
FIG. 4 is a left-side elevational view thereof, a loop portion thereof partially omitted for clarity of illustration,
FIG. 5 is a right-side elevational view thereof, a loop portion thereof partially omitted for clarity of illustration;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines showing beads and charms in FIGS. 1-7 and a book in FIG. 1 are included for the purpose of illustrating the invention in use, and form no part of the claimed design.