ARTIODACTYLA 



849 



Suida\ The Old World boars and pigs, characterised by the mobile 

 snout and terminal nostrils. There are four well-developed 

 digits on the narrow feet, but the second and fifth do not reach 

 the ground in walking. The incisors are rooted ; the upper 

 canine curves outwards or upwards. The stomach is almost 

 simple, but has more or less of a cardiac pouch and several 

 short blind saccules ; there is a ca>cum. 



Examples. — Sus, ^-^ ; Bahirusa, — -, the male with remarkable 

 3143 3123 



canines, the upper pair growing upwards from their base 

 through the skin, arching backwards as far as the forehead, 

 and sometimes forwards and downwards again, the lower pair 

 with a more or less parallel course ; Phacochcerus, the wart-hog. 



Fig. 503. — Side view of sheep's skull. 



PMX., Premaxilla ; MX., maxilla ; NA., nasal ; /., jugal ; L., lachrymal ; 

 FR., frontal; PA., parietal; SQ., squamosal; CO., condyle; PP., 

 paroccipital process. 



Dicotylidae. — The New World peccaries {Dicotyles). with a snout 

 like that of pigs, with four toes on the fore-feet, and three behind. 

 The incisors are rooted, the upper -^canines are directed down- 



^7 T Q "3 



wards, the dental formula is ''-^^. The stomach is complex, and 



3133 

 there is a caecum. 



Group 2. — Tylopoda, comprising the family Camelidce— the camels 

 of the Old World and the llamas of S. America. The limbs are 

 long, with only the third and fourth digits developed ; the two 

 metacarpals and metatarsals are united for the greater part of 

 their length, but there is a deep distal cleft ; the tips of the digits 

 have very incomplete hoofs, and the animals walk on a broad 

 pad of skin surrounding the middle phalanges. The femur is 



54 



