GENUS PHACOCHCERUS. 83 



length of body, between four and five feet ; of the tail, 

 one foot. 



The discovery of the bones of an extinct hog of huge 

 size in the cavern of Sundwick in Westphalia is due to 

 M. Goldfuss. Bones of three distinct species occur in 

 the E|jplesheim sand (Miocene division of tertiary 

 deposits, Lyell), and fossil relics of a species have been 

 found in Hutton Cave, in Mendip. and in other places. 



Several species of an extinct genus {Cheer opotamus) 

 closely allied to the hog have been discovered in the 

 gypsum of Montmartre, in certain strata in Switzer- 

 land, and in the Eocene formation of the Isle of Wight, 

 &c. 



Genus Phacoch<erus. 



The animals contained in this genus resemble the 

 hog in manners, form, and aspect, so that, were it not for 

 the peculiarity of their dentition, they would necessarily 

 be included in the genus Sus. Their dentition, how- 

 ever, is so different from that of the hog as to justify 

 their separation. Instead of presenting the ordinary 

 structure, the grinders have a great analogy with those 

 of the elephant : they are composed of vertical cylinders 

 of enamel enclosing an osseous deposit, and are cemented 

 together by cortical substance, or crusta petrosa. It is 

 long before the root of these teeth is perfected, and 

 they advance in rotation from behind forwards, pushing 

 before them the first molars, which in old individuals are 

 found to be either greatly reduced or to have entirely 

 disappeared. It is not till after ceasing to push forward 

 that the roots become consolidated. With regard to 

 number, they appear to vary. In the skull of the 

 Abyssinian Phacochoere {Ph. ^liani, Riipp.), which we 

 have carefully examined, the molars were found to be four 

 on each side above, and three below. From the first molar 

 above, which was very small, to the third, the increase in 

 size was gradual, but the fourth molar was long and nar- 

 rowed gradually as it proceeded backwards. Had the 

 animal lived much longer, it is probable that the first molar 



