During a recent visit to the famous gravel-pits at Warren Hill, Suffolk, one of the workmen handed me the bone which is described in this note. He evidently attached little importance to the specimen, which had been kept merely because it was a bone—as such are rare in the Warren Hill Gravel. The finder informed me that the specimen came from the concreted gravel—a very compact and chalky layer in the Warren Hill deposit. This claim is borne out, first, by the white, chalky appearance of the bone, which corresponds with the condition of others from the same horizon; and, secondly, by the fact that the medullary cavity of the specimen still retains some of the gravel in which it was embedded. The bone is clearly fossil, but, like others from Warren Hill, this condition is not accompanied by an addition to the weight of the specimen. The bone, in fact, probably now weighs less than it did in its pristine state—a condition of affairs, however, by no means uncommon in ancient specimens. It has assumed a consistency similar to that of chalk, and its surfaces can easily, though roughly, be scraped, or cut, by a knife.