The ornamental design for a trackball and mountingplate, as shown and described.
FIG. 1 is a perspective view of a trackball and mounting plate showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is an enlarged perspective view of the claimed region shown in FIG. 1;
FIG. 7 is an enlarged front view of the claimed region shown in FIG. 2;
FIG. 8 is an enlarged left side elevational view of the claimed region shown in FIG. 3;
FIG. 9 is an enlarged right side elevational view of the claimed region shown in FIG. 4; and,
FIG. 10 is an enlarged top plan view of the claimed region shown in FIG. 5.
The broken line showing of the remainder of the game housing in the Figures and the unshaded areas there within are for illustrative purposes only and form no part of the claimed design.