xix.] UNGULATA. 353 



third and fourth metatarsals. On the hind foot the filth 

 digit is absent though the second is tolerably well developed. 



In the Tylopoda the cuboid and navicular are distinct. 

 There is rio internal cuneiform. The second and fifth digits 

 are entirely absent. The metatarsals of the third and fourth 

 are united except at their lower extremity. The phalanges 

 resemble those of the fore foot. 



In the Tragulina the cuboid, navicular, and two outer 

 cuneiforms are united to form a single bone. The third and 

 fourth metatarsals are confluent. The second and fifth are 

 complete, extending between the small digits and the tarsus, 

 but are very slender. 



In all the Ptcora (Fig. 129) the cuboid (cb} and navicular 

 (//) are united, as are the second and third cuneiform bones, 

 and in some Deer (Ctn'ulus and Pudu) these latter are 

 further united with the cubo-navicular. The first cuneiform 

 is always distinct, though small. 1 The third and fourth 

 metatarsals (m in. and /// iv.) are united in the same manner 

 as the mctacarpals, and the phalanges of the digits are very 

 similar to those of the manus. The second and fifth 

 metatarsals are always wanting, and bones of the corre- 

 sponding digits are absent in the Giraffe and most of the 

 Oxen, Sheep, and Antelopes. In the Deer there are 

 usually three small phalanges to each of these digits, not 

 directly articulated with the rest of the skeleton. A large 

 oval sesamoid is commonly present in the plantar surface of 

 the tarsus. 



The pes of the Hyrax closely resembles that of the 

 Rhinoceros, but the ungual phalanx of the second digit is 

 cleft almost to its base. The fifth metatarsal is represented 

 by a small nodule ; the astragalus articulates with the cuboid. 



1 See Sir Victor Brooke, " Troceedings of the Zoological Society, 

 1874," p. 34. 



A A 



