The ornamental design for a hard shellboxbag with a rounded topshape, as shown and described.
FIG. 1 is a perspective view of the hard shell box bag;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right-side elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a top plan view thereof.
The broken lines showing the clasp of the hard shelled box bag in FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 7 are included for the purpose of showing environmental structure and forms no part of the claimed design.