CAMELID^? 299 



lack the pulley-like ridges and grooves on their articular 

 surfaces found in the two preceding sections ; in the tarsus 

 the navicular and cuboid remain distinct. The skull is 

 devoid of either horns or antlers. The stomach has no distinct 

 third compartment (maniplies), and the interior of the first 

 (])aunch or rumen) lacks the villi of the Pecora, while both 

 the first and second chamber are furnished with large cells 

 in which water can be stored ; the placenta is diffuse, and 

 the female has either four or two teats. With regard to the 

 structure of the feet in this group, Pocock remarks that, with 

 the exception of Orcotragus, all ruminating artiodactyles 

 " walk upon the cutaneous pad forming the sole and heel of 

 the hoof, and upon more or less of the inferior edge and apex 

 of the nail in front. The camels [and llamas] form no 

 exception to this rule, the only difference being that the 

 small nail does not invade the area of the sole to anything 

 like the same extent, and that the sole and the heel are 

 continued further backwards." 



At the present day the group has a remarkably discon- 

 tinuous distribution, the camels being restricted to the Old 

 World, and the llamas to South America ; in the Tertiary 

 period it was, however, abundantly represented in North 

 America, as it also was in Eastern Europe. 



Family CAMELID^E. 



As this is the only existing family of the section, its 



characters may be regarded as the same as those of the latter. 



The two existing genera are distinguishable as follows : — 



A. Size very large, back with one or two l!eshy humps, ears 



small Camehis. 



B. Size much smaller, back without hump, ears larger Lama. 



I. Genus CAM EL US. 



Camelus, Linn., Syst. Nat. ed. 10, vol. i, p. 65, 1758, ed. 12, vol. i, 

 p. 90, 1776 ; H. Smith, Griffith's Animal Kingdom, vol. v, p. 297, 

 1827 ; Gratj, Cat. Buminants Brit. Mus. p. 100, 1872 ; Lydelher, 

 Cat. Foss. Mamm. Brit. Mus. pt. ii, p. 139, 1885; Blanford, 

 Fauna Brit. India, Mamm. p. 558, 1891 ; Pococl-, Proc. Zool. 

 Soc. 1910, p. 972. 



