The ornamental design for the memorial marker, as shown and described.
The sole FIGURE is a front elevational view of the invention. The invention
is a memorial marker comprising a plate below and a flag above. The
mounting post and surface indicia shown in broken lines are for
illustrative purposes only, and form no part of the claimed design. The
rear of the memorial marker is flat and unornamented and forms no part of
the design. The plate and flag are of conventional thickness.