1872.] BUSK AlflMAL-EEMAINS AT ACTON AND TITRNHAM GREEN. 467 



wMch 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 sur- 

 face, 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 undistin- 

 guishable 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) diflFerent 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 de- 

 tailed 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-teri'ace Gravel, in June 1870. 



2. Fragments of the right and left scapulae. 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 entii^e 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 mea- 

 sured along the mesial side, and 2"-9 transversely*. The bone is 

 nearly entire, and, notwithstanding its porous nature, is very Httle 

 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, 



* The frontal bones in a young hippopotamus born in the Zoological Gar- 

 dens, and which died a few days after birth, measured in the same directions 

 1-9 and 2-3. 



