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To the subgenus Tetraprotodon, Hippopotamus major belongs : 
it is the most divergent form in the subgenus. The chief character- 
istics of the species are : — the shortness of the cranium, the possession 
of posterior orbits, the great elevation of the sagittal and occipital 
crests, and the excessive elongation of the upper margin of the 
orbits above the plane of the brow. 
Hippopotamus major is found in the forest-bed ; and curiously 
enough the remains of this animal that have come under my own 
notice, are nearly all of them marked Cromer : so the species seems 
to have been limited to a particular place in this deposit. 
The occurrence of Hippopotamus in the crag is extremely doubtful. 
I have seen a piece of ivory from the crag with exactly the same 
texture as the ivory of Hippopotamus : this is, so far as I am aware, 
the only evidence of its occurrence in the crag. 
Section RUMINANTIA. 
Genus BISON. 
Bison priscus (Bojanus). — In the section Buminantia, the chief 
characteristics are : — the stomach being so formed as to allow of a 
second mastication of the food, hence the name of the section ; the 
presence of incisors in the lower jaw only; the molars, almost always 
six on each side of both jaws, have their crown marked by two 
double crescents, with the convexity turned inwards in the upper 
set, and outwards in the lower ; the presence of two toes and two 
hoofs, flattened at the contiguous sides, so as to resemble a single 
hoof cloven. 
Owen in his ‘ Brit. Foss. Mamin, and Birds,’ quoting from 
Cuvier’s ‘ Menagerie du Museum d’Histoire Naturelle,’ mentions 
the chief characteristics of Bison priscus as follows : — 
“ The forehead of the ox is flat and even slightly concave ; that 
of bison is convex ; it is quadrate in tbe ox, its height, taking the 
base between the orbits, being equal to its breadth ; in the bison, 
measured at the same place, the breadth greatly exceeds the height 
in the proportion of three to two. The horns arc attached in the 
ox to the extremity of the highest salient line in the head, that 
which separates the forehead from the occiput ; in the bison this 
lino is two inches below the root of the horns : tho plane of tho 
occiput forms an acute angle with the forehead in the ox ; the 
