544 ZOOLOGY sect. 



elongated " cannon bone," like the metacarpal of the third digit 

 of the manus. In the Rhinoceroses and Tapirs all the usual 

 tarsal bones are present; in the Horses the ento-cuneiform and 

 meso-cuneiform are united. In the Artiodactyles the third and 

 fourth digits form a symmetrical pair as in the manus; and in 

 the Ruminants (Fig. 116-i) their metatarsals unite to form a 

 cannon bone. In most Ruminants there are no vestiges of the 

 second and fifth digits. In the Pigs (Fig. 1165) all the tarsal 

 bones are present. In most Ruminants the cuboid and navicular 

 are united ; in the Camels these bones are distinct, but the ento- 

 cuneiform is wanting. 



In the Hyracoidea the scapula is triangular, like that of the 

 Ungulata vera, and the spine is moderately developed and most 

 prominent in the middle. There is a large supra-trochlear fora- 

 men. The radius and ulna are complete, but often ankylosed. 

 In the carpus there is a centrale between the scaphoid and the 

 trapezoid. There are five digits, the first very small, and in some 

 represented only by a vestigial metacai^pal. 



In the femur an indistinct ridsje-like elevation is to be regarded 

 as representing the third trochanter. The foot resembles that of 

 the Rhinoceros in having three digits developed ; but there is a 

 small bone representing the fifth metatarsal, and the ungual 

 phalanx of the second is cleft. 



In the Proboscidea the coracoid-process is small. The acromion 

 presents a recurved process or metacromion, as in Rodents. The 

 clavicle is absent. The radius and ulna are permanently fixed 

 in the prone condition. The manus is short and broad, the 

 carpals are squarish, with flat articular surfaces. There is no 

 centrale ; five digits are present. The pelvis has its long axis 

 nearly vertical. The iliac crest is directed transversely, and is 

 greatly expanded ; the iliac and gluteal surfaces look almost 

 directly forwards and backwards. The pubes and ischia are com- 

 paratively small. The femur is very long as compared with that 

 of the Ungulata vera. There is no third trochanter. The fibula 

 is complete. The foot is short and broad, somewhat smaller than 

 the manus. 



Skeleton of the Carnivora. — In the Carnivora the atlas is 

 very large, with wing-like lateral processes. The neural spine 

 of' the axis is elongated and compressed, the odontoid conical. 

 The other cervical vertebra' have small spines and large transvor.<^e 

 processes. There are twenty or twenty-one thoraco-hnnbar 

 vertebnc. The most anterior thoracics have long, slender, back- 

 wardly-sloping spines. In the posterior thoracics largo meta- 

 poph3'ses and anapophyses are developed. The transverse pro- 

 cesses of the lumbar vertebra; are extremely long and the spines 

 short. Tlie sternum is long and narrow, composed usually of eight 

 or nine pieces. The sternal ribs are almost uncalcified. 



