^{page 340 note 1} Dr. G. R. Wieland, who kindly read the MS. of this paper, has furnished the following interesting memorandum: Indeed, it is curiously in accord with the foregoing facts that in the Palæozoic the thin rind of bark not only tended to outlast the wood in various types, but in turn sometimes aided in the conservation of lesser stems subsequently floated into the bark cavity. In the Laggan Bay bark cylinder figured by Seward no less than five of these floated-in Lepidodendron stems appear in fair conservation, while the fact that the cuticular layer must have been remarkably resistant is fully attested by the well-known occurrence in the Permian of Tonea of the thin bands of “paper coal”, made up as shown by Weiller of the little-changed and readily stained cuticles of Bothrodendron.