Shelf

FIG. 1 is a front/right/top perspective view of a shelf, the disclaimed portions that would be visible behind the transparent surfaces being omitted for a clear disclosure of the surface configuration;

FIG. 2 is a rear/left/bottom perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a left side elevational view thereof;

FIG. 7 is a top plan view thereof, the portions that would be visible behind the transparent surfaces being omitted for a clear disclosure of the surface configuration; and,

FIG. 8 is a bottom plan view thereof.

The broken lines represent portions of the shelf that form no part of the claimed design.