Marshall [1, Figure 9] gave an example of a polyomino, 8 copies of which
tile a square.
He asked if this was a sporadic example of a rectifiable
polyomino, or if it could be generalized to give an infinite family.
We give one way to generalize his tiling to give an infinite family of
rectifiable polyominoes; we do not claim that it is the only way to
Marshall's tiling - do you see how to generalize it?