The ornamental design for an urn having a shellshape, as shown and described.
FIG. 1 is a front perspective view of an urn having a shell shape according to the present invention.
FIG. 2 is a bottom perspective view of an urn having a shell shape according to the present invention wherein an interior perimeter of the opening is reduced to broken lines, and the broken lines form no part of the claimed design.
FIG. 3 is a rear side perspective view of an urn having a shell shape according to the present invention.
FIG. 4 is front perspective view of an urn having a shell shape according to the present invention.
FIG. 5 is a right side perspective view of an urn having a shell shape according to the present invention; and,
FIG. 6 is a left side perspective view of an urn having a shell shape according to the present invention.