FIG. 1 is a front, bottom, and right side perspective view of our new design for a portable telephone in a closed position;

FIG. 2 is a top plan view of the portable telephone of FIG. 1;

FIG. 3 is a rear elevation view of the portable telephone of FIG. 1;

FIG. 4 is a left side elevation view of the portable telephone of FIG. 1;

FIG. 5 is a right side elevation view of the portable telephone of FIG. 1;

FIG. 6 is a bottom plan view of the portable telephone of FIG. 1;

FIG. 7 is a front elevation view of the portable telephone of FIG. 1; and,

FIG. 8 is a front elevation view of the portable telephone of FIG. 1 in an opened position.

The broken line matter shown in FIGS. 1-8 is for illustrative purposes only and forms no part of the claimed design.