542 
PROFESSOR OWEN’S DESCRIPTION OF THE CAYERN OF 
is specifically identical with the skull, 976 d , from the North of Ladakh, Tibet, pre- 
sented to the British Museum by the Earl of Gifford, as of the Kiang or ‘ Wild Horse ’ 
of Tibet, which is most probably the same species as the ‘ Dshiggetai,’ or Eq. hemionus , 
from the Mongolian plains, described by Pallas*. 
I do not find the grinding-surface of the teeth of this Equine anywhere figured ; the 
outside view of the dentition in the much reduced profile of the skull in De Blainville’s 
‘ Osteographie’ (G. Equus, pi. ii.) is unavailable for such purpose and comparisons as the 
subject of the present Memoir requires. 
The series of the upper grinders resembles that in the Ass, and differs from that in 
the Horse in the greater relative extent of the premolar part. The front grinder, 2, 
terminates more obtusely ; the last grinder, m 3, is relatively of less fore-and-aft breadth 
than in most horses, especially the larger varieties ; it is less contracted behind than in 
the Ass ; it is, in the Kiang here figured, subbilobed as in the Horse. The longitudinal 
channels, f \ f, are less concave than in the Ass, and resemble more those in the Horse ; 
the intervening ridge, n, is narrower than in the Horse, but is indented in some of the 
teeth ; the lobes, a, b, are less regularly crescentic than in the Ass. The lobule, m, in 
2, is more prominent in relation to its fore-and-aft extent than in Horse or Ass; but 
in the succeeding grinders this character is lost ; the fore part, jp, of the lobule, m, is 
more produced, more equal to the hind production, than in either Horse or Ass. The 
posterior fold or indent, g, in m 3, is deeper, and the general pattern of the grinding- 
surface of that tooth differs less from that of m2 and m 1 than in Horse or Ass. The 
series of the upper molars, as in the Horse, is less curved than in the Ass. The length 
of the series is 6 inches 1 line ; that of the series of lower grinders is 6 inches 2 lines. 
These teeth are relatively narrower transversely than in the Horse ; the relative propor- 
tions of premolars to molars, in both jaws, is the same as in the Ass. 
Equus quagga or E. quaccha. — The subjects of Plate LIX. figs. 1 & 2, are from the 
skull, of a male Quagga in the British Museum, obtained from the Orange River, South 
Africa. The characters of the grinding-surface of the teeth are here, for the first time, 
figured of the natural size. The premolar part of the grinding series, like that in 
Equus caballus, is more nearly equal in longitudinal extent to the molar part, especially 
in the upper jaw, than it is in the Kiang or Ass ; and this is due to the anterior grinder, 
q> 2, being relatively shorter, and to the posterior one, m 3, being relatively longer antero- 
posteriorly, than in E. hemionus and E. asinus ; but the last molar is more contracted 
posteriorly than in the Kiang, and is there more deeply bilobed. 
In the upper molar series (fig. 1) the outer longitudinal channels resemble in shape 
those in the Horse ; but the anterior one, f, is relatively wider in jp 3 and jp 4 than in the 
Horse or Ass. The lobule, m q>, in pp 3, is less thick from without inwards than in the 
Kiang, but is as short from before backwards, differing, with the Kiang, in this respect, 
from both Horse and Ass. In the succeeding grinders it gains slightly in antero-pos- 
terior breadth, and becomes flattened on the inner side and reduced in transverse thick- 
* ‘ Novi Commentarii Academise Scientiarum Imp. Petropolitanae,’ t. xix. (1774), p. 394. 
