550 
PROFESSOR OWEN’S DESCRIPTION OF THE CAVERN OF 
spelaean Equine, the small relative size distinguishing all its kind from the larger variety, 
at least, of the modern Equus cdballus. The size of ml and m2 in Plate LX. fig. 4 
accords with that of m 1 and m 2 in fig. 3, as does also the plication of the inner enamel, 
and the form of m 3, as indicated by the germ in fig. 4, m 3. But at the stage of attri- 
tion of ml and m 2 in the young animal the proportion of length to breadth of the 
grinding-surface is nearer that in those teeth of fig. 2, Plate LX. 
Most of the Equine fossils from the Cave of Bruniquel are from young individuals. 
In Plate LX. fig. 5, is figured a fragment of the left upper jaw, with the first perma- 
nent grinder, jp 2, about to cut the gum ; the less-advanced second, jp 3, and third, jp 4, 
premolars had not displaced the corresponding deciduous teeth, d 3, d 4, which had 
been worn nearly to the much absorbed stumps. This phase of dentition corresponds 
with that of a colt of Equus caballus between two years and two years and a half old. 
The upper deciduous molars, d 3, d 4, of Eq. sjpelceus (fig. 6, Plate LX.) differ from those 
of the Zebra and Ass, not only in their larger size, but in their greater breadth trans- 
versely, relatively to their length of grinding-surface, albeit they show the degree of 
narrowness which characterizes the milk-molars in Equus caballus (Plate LVII. fig. 3). 
The lobule m is relatively larger and broader from without inward. 
In the subject of Plate LVII. fig. 7, the first lower permanent grinder, jp 2, has come 
into place and has been worn sufficiently to expose the characteristic markings of its 
grinding-surface. The correspondence of the pattern to that in the more worn homo- 
logue of the mature Cave-Equine (Plate LVII. fig. 5, jp 2) is instructively close. The 
anterior division of the terminal expansion of the fold g shows the same crenation of the 
outer enamel-wall ; the fold k has the same simple bifurcation. The correspondence is 
instructively close, also, with jp 2 in Plate LVII. fig. 6. The permanent mid incisors, i 1, 
fig. 7, have displaced their deciduous predecessors, and have been worn down to the 
‘ mark.’ The contiguous permanent incisors, i 2, are just appearing above the alveoli, 
and the summits of the permanent canines, c, are visible. This state of dentition indi- 
cates a young stallion, or colt, of about three years. The correspondence with the 
Equines from the French quaternary or pleistocene sedimentary bed (Plate LVII. fig. 6), 
in the length of the diastema and the position of the canines, is instructively close ; the 
larger size of the wedge-shaped mid incisors, i 1 in fig. 7, is due to the limitation of 
attrition ; in the older individual these teeth are worn nearly to their inserted fang 
(fig. 6, i 1). 
In the subject of Plate LVII. fig. 8, the permanent canine, c, has pushed through the 
socket ; its unworn summit shows the folding back of the margins of the enamel, causing 
the bicanaliculate inner or hinder surface characteristic of that tooth in Equines. In 
the lower molar series of the Equine from the freshwater beds of the Puy-de-Dome, 
the fold f so nearly touches the same part of the fold g as to suggest that they may 
have been continuous at the earlier stage of attrition shown in the young colt from 
Bruniquel. 
