on M^ Sivatherium giganteum. 199 



union of the latter with the nasals. The same cause has rendered ob- 

 scure the connexions of the maxillaries with the nasals, and the depth and 

 size of the nasal echancrure or sinus. 



The jugal bone is deep, massive and rather prominent. Its lower border 

 falls off abruptly in a hollow descending on the maxillaries; the upper en- 

 ters largely into the formation of the orbit. The posterior orbital process 

 unites with a corresponding apophysis of the frontal, to complete the cir- 

 cuit of the orbit behind. The zygomatic apophysis is stout and thick and 

 rather flat. No part of the arch, either in the temporal or jugal portions, 

 is prominent: the interval between the most salient points being greatly 

 less than the hind part of the cranium, and slightly less than the width 

 between the bodies of the jugals. 



The extent and form of the lachrymals, cannot be made out, as there 

 is no trace of a suture remaining. Upon the fossil, the surface of the la- 

 chrymary region passes smoothly into that of the adjoining bones. There 

 is no perforation of the lower and anterior margin of the orbit by lachry- 

 mary foramina, nor any hollow below it indicating an infraorbital or la- 

 chrymary sinus. It may be also added, what was omitted before, that 

 there is no trace of a superciliary foramen upon the frontal. 



The orbits are placed far forwards, in consequence of the great produc- 

 tion of the cranium upwards, and the shortness of the bones of the face. 

 Their position is also rather low, their centre being about 3-6 inches below 

 the plane of the brow. From a little injury done in chiseling off the stone, 

 the form or circle of the different orbits does not exactly correspond. In 

 the one of the left side, which is the more perfect, the long axis makes a 

 small angle with that of the plane of the brow : the antero-posterior diameter 

 is 3-3 inches, and the vertical 27 inches. There is no prominence or in- 

 equality in the rim of the orbits, as in the Ruminantia. The plane of the 

 rim is very oblique : the interval between the upper or frontal margins of 

 the two orbits being 12-2 inches, and that of the lower or molar margin 

 16-2 inches. ° 



Dimensions of the Skull of the Sivatheriura giganteum*. 



•ri .1 , • • ,- , ^ Eng. Inches. Metres. 



l<rom the anterior margin of the foramen magnum to the 



alveolus of first molar 18'85 "478 



From do. to the truncated extremity of the muzzle 20-6 -5268 



From do. to the posterior margin of the last molar 10-3 -262 



From the tip of the nasals to the upper fractured margin 



of the cranium jg-Q -4568 



From do. do. to do. along the curve 19-0 -4822 



From do. do. along the curve, to where the nasal arch 



begins to rise from the brow y-g .jgg 



From the latter point to the fractured margin of the cra- 



,,"'""!■ 11-2 -284 



from the tip of the nasals to a chord across the tips of the 



„ horns 8-5 -216 



l<rom the anterior angle, right orbit, to the first molar ... 9-9 -251 

 From the posterior do. do. to the fractured margin of the 



cranium \o.\ .3Q75 



Width of cranium at the vertex (mutilation at left side 



restored), about 22"0 '559 



Do. between the orbits, upper borders ]2-2 "3095 



Do. do. do. lower borders 16'2 •4108 



Do. behind the orbits at the contraction of the frontal... 14-6 3705 



Do. between the middle of the zygomatic arches 16-4 -4168 



• To facilitate comparison with the large animals described in Cuvier's Oise. 

 mens Fussiles, tiie dimensions are also given in French measure. 



