FIG. 1 is a front, top and left side perspective view of a portion of a sample rack showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is an enlarged view of the portion shown in box 3 in FIG. 2;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a rear elevational view thereof.

The broken lines shown are for illustrative purpose and form no part of the claimed design. The alternate long and short dash lines define, but are not included in, the boundaries of the claimed design.