We claim the ornamental design for a bathtub, as shown and described.
FIG. 1 is a top isometric view of another embodiment of the claimed design;
FIG. 2 is a another top isometric view of the claimed design of FIG. 1;
FIG. 3 is a front view of the claimed design of FIG. 1;
FIG. 4 is a rear view of the claimed design of FIG. 1;
FIG. 5 is a top plan view of the claimed design of FIG. 1;
FIG. 6 is a bottom view of the claimed design of FIG. 1;
FIG. 7 is a left-side view of the claimed design of FIG. 1;
FIG. 8 is a right-side view of the claimed design of FIG. 1;
FIG. 9 is a sectional view of the claimed design of FIG. 1 taken along line 9-9 of FIG. 5; and,
FIG. 10 is a sectional view of the claimed design of FIG. 1 taken along line 10-10 of FIG. 5.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. The dash-dot lines in the drawings define boundaries of the claimed design and form no part thereof.