Fig. 1. Ornithichnites giganteus. The natural cast here figured represents the form and size of the foot, and part of the claws. (Hitchcock.)

Fig. 2. Ornithichnites diversus; with impressions of the appendage to the heel, drawn from a plaster mould sent by Prof. Hitchcock to the Geol. Soc. of London. (Original.)

Fig. 3. Track of a small animal on Oolitic slate near Bath. See Journal of Royal Institution of London, 1831, p. 538, Pl. 5. (Poulett Scrope.)*

Mr. Poulett Scrope has presented to the Geol. Soc. of London a series of Slabs selected from the tile quarries worked in the Forest Marble beds of the Oolite formation near Bradford and Bath. The surface of these beds is covered with small undulations or ripple markings, such as are common on the sand of every shallow shore, and also with numerous tracks of small animals (apparently Crustaceans) which traversed the sand in various directions, whilst it was yet soft, and covered with a thin film of clay. These footmarks are in double lines parallel to each other, shewing two indentations, as if formed by small claws, and sometimes traces of a third claw. (See Pl. 26^b, Fig. 3.) There is often also a third line of tracks between the other two, as if produced by the tail or stomach of the animal touching the ground. Where the animal passed over the ridges of the ripple markings or wrinkles on the sand, they are flattened and brushed down. Thus a ridge between b. and d. (Pl. 26^b, Fig. 3) has been flattened, and there is a hollow at e. on the steep side of the ridge, which may have been produced by the animal slipping down or climbing up the acclivity.