|i NOTE ON THE FOSSIL HIPPOPOTAMUS 



Sivalik fossil the proportion is as 3 to 2, shewing as was before remarked an 

 increased height of the occipital crest. — To proceed therefore to the lower 

 jaw : 



In comparing the lower jaw with that of the existing animal, indepen- 

 dently of the additional incisors, we have a marked difference and distinction 

 in the form of the ramus, the enormous descending process of which is if 

 anything more extravagantly developed. This strange appendage peculiar 

 to the genus, and formed for the attachment of the masseter and temporal 

 muscles is here of a form less tapering and more deep and massive in its 

 proportions than in the existing animal ; the posterior margin is more round 

 and the anterior, or that descending from the base of the maxillary bone, 

 which in the existing animal is curved and pointed forwards, is here blunt 

 and unmarked by any peculiarity of form. This angle is inclined outwards, 

 and the outer surface is as depressed for the reception of the muscles as that 

 of the living Hippopotamus. We observe no increase of height in the 

 coronoid process, but it differs from the living animal in not being projected 

 so much forward. There appears to be no difference in the condyles nor in 

 their position with reference 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 symphisis, and only broken at the posterior extremities) is 

 inclined to the outwardly curved direction, described as a peculiarity in the 

 upper surface : 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. The canines protrude from the 

 alveoli considerably, in a curve slightly inclined backwards at the point, 

 which is obliquely 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 

 incisive teeth themselves differ as was before remarked, from the existing 

 animal, the large central incisors of which are here replaced by much 

 smaller ones. The number of incisors in the fossil is six, of nearly equal 

 dimensions, cylindrical, inclined outwards at an obtuse angle to the plane 



