1836.] Note on Mastodons of the Seivalihs. 769 



type of the same genus or co-genus (for it may be permitted so to 

 designate the elephant) which has been left to us — so different indeed, 

 as to completely modify the construction of the head, and the 

 arrangement of the muscular and fleshy matter that must have belong- 

 ed to it. 



"Without entering into any minutiae of detail on the peculiarities of 

 the head, of which the drawings will give a representation, and which 

 detail will be reserved until our collections enable us to bring under 

 one view all the varieties of this genus that the Sewaliks may contain, 

 it will be sufficient, in announcing this very interesting addition to 

 our cabinet, to draw attention to a few leading points. 



In the skull of the existing elephant, the excess of longitudinal 

 measurement, over that in the contrary direction, owing to the great 

 development of the superior portion of the cranium, is one of the 

 most marked peculiarities of its form ; the height from the external 

 nasal opening to the top or apex of the cranium is immense, although 

 undergoing modification from age ; this excessive development not 

 being derived from any increase of size to the cerebral cavity, but to 

 a wide space composed of cellular bone or diploe, giving an external 

 and deep covering to all that space occupied by the brain ; the size 

 of the orbit is small with comparison to the temporal region ; the 

 large external nasal aperture is situated between the orbits ; and the 

 front in the Indian species is slightly depressed : — now in turning to 

 the fossil, we find that the whole of these peculiarities, are either 

 reversed, or modified in an extraordinary degree. 



The elevated and massive cranium does not exist, the slope towards 

 the occipital and foramen magnum commencing from the top of the 

 external nasal opening, and falling off to the rear in an abrupt angle ; 

 the size of the orbit is large, and its encircling bones massive and 

 prominent ; the space between the orbits to the front continued up 

 to the nasal opening, is depressed to an enormous extent, and the two 

 lines of alveoli of the tusks strongly marked ; the temporal fossae are 

 comparatively small with those of the existing elephant, and the 

 temporal bones ; which although broken off in the specimen from 

 which the drawing is taken, exists in another skull in our possession, 

 appearing to be large and composed of cellular bone. The angle 

 formed by the tusks with the grinding surface is more obtuse than in 

 the existing elephant, and the form of head, instead of possessing the 

 proportion assimilating the skull of the elephant to that of man, may 

 be considered as nearly square, or perhaps possessing a breadth in 

 greater proportion than the length. The height of the maxillary 

 bones which is great in the elephant, is here much exaggerated, and 

 5 H 



