FOSSIL HORSE. 387 
Figure 143 shows the grinding surface of the third 
molar, right side of the upper jaw, in a fossil from the 
cave of Kent’s Hole, Torquay. It presents the same fos- 
silised condition as the bones and teeth of the extinct 
Rhinoceros and the great Carnivora from the same de- 
pository. The upper molars of the Horse are slightly 
curved ; and a fossil species, contemporary with the Mega- 
therium in South America, differs from the existing Horse 
by the greater degree of that curvature: but there is no 
such difference in the present fossil, which is of equal 
length with a large Horse’s tooth compared, viz., three 
inches and a quarter; neither is there any modification 
of the pattern of the enamel folds on the grinding surface 
deserving to be regarded as specific. This degree of dif- 
ference is indicated only by the smaller transverse as com- 
pared with the antero-posterior diameter ; and the same 
difference of proportion, as compared with the teeth of 
the common existing Horse, is shown in the figure of the 
upper molar from the cave at Kirkdale, in the ‘ Reliquie 
Diluviane,’ pl. vii., fig. 7. In general, I have found that 
Fig. 144. 
3rd lower molar, recent horse, 3rd lower molar, Equus fossilis, Oreston, 
Nat. size. Nat. size. 
the lower molar teeth of the fossil Hqguus present the 
same difference in their narrower transverse diameter : 
this character is shown in the cut of the grinding surface 
2c2 
