544 UNGULATES. 



likewise amongst the ancient extinct aberrant forms, the Hippohyus{\) 

 presents almost a ruminant pattern of the grinding surface, whilst 

 the Chaeropotamus manifests in its whole dentition a close resemblance 

 to the plantigrade Carnivora. 



The folds of the dental capsule upon the coronal surface of 

 the molar teeth of the typical Hogs are shorter than in other 

 hoofed Mammals, but are very numerous, and produce a multicuspid 

 or rather multituberculate grinding surface, especially in the last 

 molar, which is commonly much larger than the rest. The canines 

 form projecting tusks, and are remarkable in most Suidce for 

 their extraordinary size, shape, and direction, especially in the 

 males. The incisors are less constant, varying in number in 

 different genera. The progressive increase of size in the molar 

 teeth as they are situated further back in the mouth, may also be 

 noticed as a family characteristic, which, with the complication of 

 the crown and the development of the tusks, reaches its maximum 

 in the Phacocheres. 



196. Sus. — The wild progenitor of our domestic breeds of Hog 

 {Sus scrofa, Linn.) offers as the normal formula : — 



3—3 1— I 4—4 3—3 . . .-Tj, , . ^ ^ , . 



*^- ^; ^- IZT' i'^- :izii *^- iziJ = 44. (PL 140, fig. 1.) 



The upper incisors decrease in size from the first to the third : 

 the first has a short, strong, obliquely bevelled crown, which 

 inclines towards and touches that in the other intermaxillary by its 

 produced inner part; the crown, before it is worn, presents 

 a depression ; it is implanted by a short, thick, curved fang ; 

 this incisor is relatively larger in the Sus larvatus than in the 

 Sus scrofa. The second incisor, in the common Hog, has a 

 crown as broad as the first, but shorter and thinner ; its edge 

 is trenchant and dentated, but is soon worn down : in this state 

 the abraded surface of both incisors shows a dark mark in the 

 centre. The third is a very small tooth, a little removed from the 

 second. The form and position of the short vertical crowns of 

 the upper incisors remind one of those of the Kangaroo ; and the 

 resemblance is carried out by the procumbent position of the 



(1) An extinct genus so called by its Discoverers, Captain Cautley and Dr Falconer. 



