MEGACEROS HIBERNICUS. 449 
of the palm are generally the shortest, and curve in a 
direction opposite to the former. 
Camper* first recognised the well-marked differences be- 
tween the Megaceros and the Elk, in the conformation of 
the skull. The peculiarly developed and prehensile upper 
lip of the Elk is associated with an unusual elongation of 
the intermaxillaries and nasal apertures, and a shortening of 
the nasal bones; but the skull of the Megaceros closely con- 
forms to that of the ordinary deer, and more especially the 
Rein-deer, as Cuvier+ has pointed out. The dentition of 
the Megaceros displays the ordinary Ruminant type, viz. : 
i. 9, p. 3-3, m. 3-332: that is, there are eight incisors 
in the lower jaw, and six molars on each side of both jaws, 
the first three being premolars, the last three true molars. 
There are no canines or their rudiments retained in either 
sex.| The subjoined figure of the first true molar (fourth 
of the series, counting back- Fig. 183. 
wards,) in the upper jaw, well 
illustrates the peculiar charac- 
ter of the grinding surface of 
the molar teeth in a Ruminant 
quadruped ; the body of the 
tooth is divided into two lobes 
(a, 6.) placed one in front of 
the other, with the inner side 
Upper molar of Megaceros, nat. 
convex, the outer side concave size. 
or sinuous from a slight convexity at the middle part. 
Each lobe is subdivided by a vertical cleft, ¢, lined by 
enamel and bent, with its convexity turned towards 
the inner side and its concavity towards the outer 
* Nova Acta Acad. Petropol. ii. p. 258. i) Op. cite pe 10 
+ The two exterior incisors of the under jaw represent the lower canines of the 
horse, but there are no rudiments of upper canines, as there are in the Red-deer 
and Rein-deer. 
GG 
