On some Natural Casts of Reptilian Footprints in the Wealden Beds of the Isle of Wight and of Swanage

Since my last communication to the Society, in 1854, on the subject of Wealden Footprints (Quart. Journ. Geol. Soc. vol. x. p. 456, &c.), I have met with several other specimens, some of them of very considerable size, in the Wealden beds near Compton Bay, Isle of Wight. Of these I have secured seven specimens. They are large trifid casts, each having theposterior portion more or less elongated, like the specimen indicated by the diagram, fig. 1, p. 396, Quart. Journ. Geol. See. vol. viii. One of them(fig. 2)I had raised from its natural position, as a mass attached to a thin bed of hard sand-rock, in reddish clay, on the shore at low water, between Brook Point and the Chine to the west of it (see section, fig. 1). The other specimens were found loose on the clay of the shore at low water, and were more or less worn by waveaction. These all have the usual three divergent, toe-like projections, varying in proportional size in the several specimens, and radiating from a palmar mass; but, in addition, the hinder portion forms a long tapering projection. In the largest (figs. 2 & 3), the whole length of the block is 3 feet 4 inches, but 3 feet 7½ inches if measured along the curvature of the base; the breadth across the toes is 27 inches; across the “heel,“ just behind the central mass, 14 inches. The thickness, where the imprint of the toe (A) is represented by