THE recent stranding of a narwhal (Monodon monoceros) at Rainham, Essex, is a record of considerable interest. This species is usually limited to Arctic waters, although it occasionally penetrates into the North Sea. The infrequency of its occurrence off the British coast may be gauged by the fact that since 1588, when one was found on the coast of Norfolk, as recorded by Purchas1, only three other instances until the present one are known. These were one on the Isle of May in the Firth of Forth, in June 1648 ; one near Boston, Lincolnshire, in February 1800 ; and one in the Sound of Weesdale, Shetland, in September 1808.