136 FAUNA ANTIQUA SIVALENSIS. 



to the form of the jaw ; the line of the grinding surface (the 

 specimen from which we draw this description is a lower jaw 

 joined at the symphysis, and only broken at the posterior ex- 

 tremities) is inclined to the outwardly curved direction, described 

 as a peculiarity in the upper surface (PI. XII. fig. 1) : the teeth 

 do not appear to differ from those of the animal now living, 

 but the space between the front molar and the canine is, as in 

 the upper jaw, more contracted (fig. 2). The canines protrude 

 from the alveoli considerably, in a curve slightly inclined back- 

 wards at the point (fig. 3), which is obliqviely truncated on the 

 internal surface, from the root or point where it leaves the 

 alveolus to the tip. The space for the incisors and the in- 

 cisive teeth themselves diflFer, as was before remarked, from 

 those of the existing animal, the large central incisors of which 

 are here rej)laced by much smaller ones. The number of in- 

 cisors in the fossil is six, of nearly equal dimensions, cylindrical, 

 inclined outwards at an obtuse angle to the plane of the 

 grinding surface, and sharply truncated at the mtemal side 

 at the point (fig. 2). In taking the dimensions of the incisive 

 teeth of the upper and lower jaw from two specimens of 

 adult animals we find their proportions as follows : — 



Diameter of incisor — lower jaw 



Ditto ditto Tipper jaw 



If there is any fixed difference in the size of the teeth of 

 each jaw, it exists in the second incisor being a little less 

 than the others. It may be necessary to note here with re- 

 gard to the number of molars in the lower jaw, that amongst 

 the great number of specimens before us of animals of all 

 ages, we see no mark or vestige of the first milk tooth, or 

 that which, as was mentioned before, falls and is not replaced ; 

 and the space between the adjacent molar and the canine is 

 so contracted as hardly to admit of room for another tooth ; 

 but as this tooth exists in the upper jaw in every specimen in 

 our possession, we may infer that its non-presence in the 

 lower jaw is accidental.^ In viewing the lower jaw in profile, 

 we see that the anterior angle below the canines is somewhat 

 more abrupt, and more inclined to tiie form represented as 

 belonging to the European fossil species ; the depth of the 

 inferior maxillary is more regular, and the form of the pos- 

 terior branches, as before described, very different. The lower 

 surface exhibits a width of symphysis equal to that of the 

 living animal, and the angle formed by the branching off of 

 the two sides is also similar. The width across the muzzle 

 from the exterior side of the canine alveolus to the other is 



' See Description of Plates in Fauna Antiqua Sivalensis (PI. Ixii. figs. 2 and 3). — [Ed.] 



