The ornamental design for a cremationurn, as shown and described.
FIG. 1 is a top plan view of a cremation urn showing my new design;
FIG. 2 is a front elevational view of the cremation urn;
FIG. 3 is a right side elevational view of the cremation urn; and
FIG. 4 is a bottom plan view of the cremation urn.
The left side is identical to the right side, and the rear is identical to
the front. The top, sides, front and rear are all of a marble surface as
partially shown in FIG. 3.