MEGACEBOS 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*f- has pointed out. The dentition of 

 the Megaceros displays the ordinary Ruminant type, viz. : 

 * TP P' %-%i m " t-f =32 : 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, i,) 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, 0, 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. f Op. cit. p. 78. 



J 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. 



G G 



