The ornamental design for a watch casing and portion of a strap, as shown and described.
Description:
FIG. 1 is a top plan view of a watch casing and portion of a strap showing my new design;
FIG. 2 is a left side elevational view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a first end elevational view thereof;
FIG. 5 is a second end elevational view thereof; and,
FIG. 6 is a bottom plan view.
The speckled dots are intended to illustrate a contrast in color and/or material used to construct and illustrate the claimed invention. The fact that the drawings illustrate dots, in and of itself, is not material to the invention.