Page:Quarterly Journal of the Geological Society of London, vol. 28.djvu/563

1872.] which species such abundant remains are to be seen in the collection of Sir Antonio Brady. This bone appears to have been met with quite at the bottom of the Thames valley, at a height of from 10 to 20 feet only above high-water mark, and at a depth of 8 feet from the surface, beneath a layer of fine yellow sand.

2. Equus caballus.—The only indubitable ancient vestige of the horse in this deposit is a solitary lower molar, which is undistinguishable from that of the existing form.

3. Hippopotamus major.—The remains of the Hippopotamus are rather numerous, belonging, as it would seem, to individuals of at least two (or perhaps three) different ages—one quite mature, one at the age at which the proximal epiphysis of the tibia is still ununited and the epiphyses of the metatarsals still show the line of junction, and one apparently a much younger animal, probably only a few months old. Though most of these bones are much broken, they appear but very little water-worn or rolled. As they constitute an interesting part of the collection, I propose to give a somewhat detailed account of them. They consist of:—

1. The occipital crest of a fully mature animal. It is about the same size as that of the existing species, as shown in the skeleton in the College of Surgeons, but differs from it in the much greater depth and smoothness of the anterior concavities. Found in Brown's orchard, Mid-terrace Gravel, in June 1870.

2. Fragments of the right and left scapulæ. Found in the same locality.

3. Several large fragments of the left os innominatum, including part of the sacro-iliac articular surface. As the fractured edges all appear to be recent, it is not improbable that further search would have led to the discovery of the entire bone.

4. The proximal epiphysis of the left tibia, wanting part of the external articular facet, but otherwise entire and little worn.

5. The left fourth metatarsal of a fully mature animal (Pl. XXIX, fig. 1), very nearly perfect, as it only wants the hinder apophysis. The bone is 5⋅5 inches long, and its least circumference 5⋅1, giving a perimetral index of ⋅927.

6. The right fourth metatarsal of a young animal (fig. 2), inasmuch as the line of junction of the epiphysis is indicated by a deep groove. The bone is 5⋅75 inches long, and its least circumference 4⋅2, giving a perimetral index of ⋅730.

7. The left frontal of apparently a very young animal, to judge from the size and porous structure of the bone, which is 3"⋅4 measured along the mesial side, and 2"⋅9 transversely. The bone is nearly entire, and, notwithstanding its porous nature, is very little worn; so that the depression for the reception of the nasal is sharply defined, and the cerebral sulci on the inner surface remain quite distinct.

This specimen suffices to show, did any doubt exist on the matter,