The ornamental design for an inkcartridge, as shown and described.
FIG. 1 is a bottom front right side perspective view of an ink cartridge showing the new design.
FIG. 2 is a top rear right side perspective view thereof.
FIG. 3 is a front view thereof.
FIG. 4 is a rear view thereof.
FIG. 5 is a left side view thereof.
FIG. 6 is a right side view thereof.
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The dashed lines immediately adjacent to the claimed areas of the two rimmed recesses on either end of the right side of the cartridge in FIG. 6 represent the boundaries of the claimed design. The remaining dashed lines in the figures illustrate the portions of the design that form no part of the claimed design. None of the broken lines form any part of the claimed design.