The ornamental design for a shower enclosure, as shown and described.
FIG. 1 is a perspective view taken from the top and front of a shower
enclosure embodying my new design;
FIG. 2 is an elevational view directly facing the interior side of the
right wall, the view directly facing the left wall interior side being the
mirror image of the view of FIG. 2;
FIG. 3 is a top plan view thereof;
FIG. 4 is a cross-sectional view taken on line 4--4 of FIG. 1; and,
FIG. 5 is a cross-sectional view taken on line 5--5 of FIG. 1.