FIG. 1 is a top perspective view of the dome lid for a mug or tumbler showing my new design;

FIG. 2 is a right side elevation view thereof, the left side view being a mirror image;

FIG. 3 is a front view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a right side elevation view thereof, the tumbler and straw are shown in broken lines.

The broken lines showing FIGS. 1-3 and 5 are for illustrative purposes only and form no part of the claimed design.