The ornamental design for a shellshapedbonnet, as shown and described.
FIG. 1 is a top perspective view of a shell shaped bonnet in an expanded configuration showing my new design;
FIG. 2 is a front elevation view of the shell shaped bonnet;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top plan view of the shell shaped bonnet portrayed in an expanded configuration; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the drawings depict stitching that form no part of the claimed design. The D-shaped broken lines in FIGS. 3, 5, and 6 depict environment and form no part of the claimed design.