I have long felt, for reasons which need not be detailed here, that the Red Rock Series of the Exeter district was mainly of subaërial origin, the breccias and associated sands having accumulated on a strip of country bounded on the west by high hills carved out of the folded Culm, while a large sheet of water lay to the east. The frequent indications of aqueous deposit would be due to variations in the level of the water such that it occasionally over-spread much of the littoral region, and rearranged and levelled the subaerial accumulations. Such a district seems to be exactly suited for the preservation of the footprints of any animals which might descend from the hills to wander over the low-lying sandy shores. I have, therefore, repeatedly searched the surfaces of blocks freshly fallen from the cliffs near Exmouth, where the ‘Lower Marls with occasional Sandstones’ reach the coast, and every other section that I could find in which the natural surfaces were laid bare. Sun-cracks on the surfaces of thin lenticular seams of marl are often to be found, as well as other signs of the s opposed conditions. The upper part of some of the sandstones weathers out in a curious way, leaving an irregular network of concretionary structures, strongly suggestive of a matted network of underground stems, such as those of the sand Carex or the recent Equisetaceas. But nothing of undoubtedly organic origin has been found. Away from the coast suitable exposures are rare.