The ornamental design for a periodicaldisplaycase, as shown and described.
FIG. 1 is a top, front perspective view of the periodical display case showing my new design;
FIG. 2 is a top view of the periodical display case of FIG. 1.
FIG. 3 is a front view of the periodical display case of FIG. 1.
FIG. 4 is a right side view of the periodical display case of FIG. 1, the left side of the periodical display case being a mirror image of the right side.
FIG. 5 is a back view of the periodical display case of FIG. 1; and,
FIG. 6 is a bottom view of the periodical display case of FIG. 1.
The broken lines showing four periodicals are for environmental purposes only and form no part of the claimed design.