One of us has been engaged for some years in the study of the Pleistocene gravels and associated deposits of the Cambridge district, and eventually proposes to give a full account of the results obtained. Meanwhile, considering the importance of noting the conditions under which Pleistocene floras are preserved, in order to draw attention to their probable occurrence under similar conditions elsewhere, it is thought advisable to give a preliminary account of the discovery of an Arctic flora of this date in a pit at Barnwell, a suburb of Cambridge, long noted for its Pleistocene deposits.