SIVATIIERIUM GIGANTEUM. 



2.51 



Dimensions of the Teeth. 



Last molar right side . 

 Penultimate ditto 

 Antepenultimate ditto. 

 Last simple molar 

 Second ditto 

 Erst ditto . 



Space occupied by the line of molars, 9'8 inches. 



Bones of the Head and Face. — From the age of the animal 

 to which the head had belonged, the bones had become an- 

 chylosed at their commissures, scfthat every trace of suture 

 has disappeared, and their limits and connections are not 

 distinguishable. 



The frontal is broad and flat, and slightly concave at its 

 upper half. It expands laterally into two considerable swel- 

 lings at the vertex, and sweeps down to join the temporals in 

 a,n ample curve, and with no angularity. It becomes nar- 

 rower forwards to behind the orbits, and then expands again 

 in sending off an apophysis to join with the malar bone and 

 complete the posterior circuit of the orbit. The width of the 

 bone where narrowest, behind the orbit, is very great, being 

 16"2 inches. Partly between and partly to the rear of the 

 orbits there arise, by a broad base passing insensibly into the 

 frontal, two short thick conical processes. They taper rapidly 

 to a point, a little way below which they are mutilated in the 

 fossil. They start so erect from the brow that their axis is 

 perpendicular to their basement, and they diverge at a con- 

 siderable angle. From their base upwards they are free from 

 any rugosities, their surface being smooth and even. They 

 are evidently the osseous cores of two infra-orbital horns 

 (Plate XIX. and Plate XX. fig. 2). From their position and 

 size they form one of the most remarkable features in the 

 head. The connections of the frontal are nowhere distin- 

 guishable, no mark of a suture remaining. At the upper end 

 of the bone the skull is fractured and the structure of the 

 bone is exposed. The intei^nal and outer plates are seen to 



