567 



3407. The cranium of a Hippopotamus amphibius. 



The last molar has come into place, but is unworn : the hist deciduous molar is retained on 

 the left side, but has been shed, or removed on the right side to show the summit of the more 

 simple last premolar, p 4, which was about to emerge. 



Presented by Richard Wettank, Esq., F.R.C.S. 



3408. The skull of a female Hippopotamus amphibius. 



The last molars, m 3, have half protruded from their sockets in the lower jaw, where the 

 last premolars have risen into place. In the upper jaw the last molars are beginning to pro- 

 trude, and the last premolars are less advanced, especially on the left side, where the last deci- 

 duous molar seems to have been artificially removed to show the point of its successor. The 

 sockets of the anterior premolars, ;; 1, are obliterated. 



Hunterian. 



3409. The skull of a female Hippopotamus amphibius. 



It shows a similar stage of dentition to the foregoing. The points of the last premolars 

 have protruded in both jaws, but they are less advanced than the last molars : traces of the 

 sockets of the first premolars, p 1, remain in the upper jaw. 



Hunterian. 



3410. The skull of a young Hippopotamus amphibius. 



The last molars are exposed in, but have not protruded from, their formative alveoli, and 

 the last deciduous molars, d4, have not been shed : they are much worn in both jaws. The 

 sockets of the first premolars remain in the upper jaw. 



Hunterian. 



3411. The cranium of a young Hippopotamus amphibius. 



The first, second and third premolars, and the first and second true molars have come into 

 place : the last milk-molar, d 4, is retained : the last true molar may be seen in its formative 

 socket, from which it has not emerged. The protruded parts of the permanent incisors and 

 canines are each between two and three inches in extent. 



Hunterian. 



3412. The skull of a younger Hippopotamus amphibius. 



The teeth in place in both upper and lower jaws are, the permanent incisors and canines, 

 the first premolars, the second, third and fourth milk-molars, and the first true molars. 



The canines are larger than the incisors : the median incisors are much more developed 

 than the lateral ones in the lower jaw. The outer parietes of the formative alveoli of the 

 second, third and fourth premolars have been removed from the left ride of both jaws. 



Hunterian. 



