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history of Fossil Fishes is the branch of Palæontology which has hitherto received least attention, in consequence of the imperfect state of our knowledge of existing

smaller print of a fore foot, four inches long and three inches wide. These footsteps follow one mother in pairs, at intervals of fourteen inches from pair to pair, each pair being in the same line. Both large and small steps have the great toes alternately on the right and left side; each has the print of five toes, and the first, or great toe is bent inwards like a thumb. The fore and hind foot are nearly similar in form, though they differ so greatly in size.

On the same slabs are other tracks, of smaller and differently shaped feet, armed with nails. Many of these (Pl. 26') resemble the impressions on the sandstone of Dumfries, and are apparently the steps of Tortoises.

Professor Kaup has proposed the provisional name of Chirotherium for the great unknown animal that formed the larger footsteps, from the distant resemblance, both of the fore and hind feet, to the impression of a human hand; and he conjectures that they may have been derived from some quadruped allied to the Marsupialia. The presence of two small fossil mammalia related to the Opossum, in the Oolite formation of Stonesfield, and the approximation of this order to the class of Reptiles, which has already been alluded to, (page 64, note,) are circumstances which give probability to such a conjecture. In the Kangaroo, the first toe of the fore foot is set obliquely to the others, like a thumb, and the disproportion between the fore and hind feet is also very great.

A further account of these footsteps has been published by Dr. Sickler, in a letter to Blumenbach, 1834. Our figure (Pl. 26',) is copied from a plate that accompanies this letter; on comparing it with a large slab, covered with similar footmarks, from the same quarries, lately placed in the British Museum, (1835) I find that the representations, both of the large and small footsteps, correspond most accurately. The hind foot (Pl. 26″,) is drawn from one on this slab. Pl. 26‴ is drawn from a plaster