PERISSODACTYLA 759 



from a West African forest, has a shorter neck, and the horns 

 are on the frontals. It links the giraffe to the extinct 

 Palceotragus. 



Antilocapridss, represented solely by the prongbuck (Antilocapra 

 americana), a North American animal, with most of the char- 

 acteristics of Bovidae. The horny sheath bears one branch, and 

 is periodically detached from the bony core. 



Bovidae, the hollow-horned Ruminants, widely distributed throughout 

 the world, but without indigenous representatives in Australia, 

 South or Central America. The second and fifth digits may be 

 completely absent, but are often represented by minute hoofs and 

 supporting nodules of bone. The frontal appendages, if present, 

 consist of a solid bony core growing from the frontal, and a much 

 longer sheath of horn, which grows at the base as it is worn away 

 at the tip. They are not deciduous, and are usually present in 

 both sexes, though larger in the males. 

 Examples. Antelope ', Gazella, Capra, Ovis, Bos. 



Sub-Order PERISSODACTYLA 

 Horses, Tapirs, Rhinoceros, and their extinct allies. 



The middle or third digit of fore- and hind- feet is larger 

 than the others, and symmetrical on itself. It may be the 

 only complete digit, as in the horse, or it may be accom- 

 panied by the second and the fourth, and in the fore-foot of 

 tapirs and some extinct forms by the fifth, digit. No modern 

 forms have any trace of the first digit. The astragalus 

 has a pulley-like surface above for articulation with the 

 tibia ; its distal surface is flattened and unites to a much 

 greater extent with the navicular than with the cuboid. 

 The last-named bone is of less importance than in the 

 Artiodactyla. The calcaneum does not articulate with 

 the lower or distal extremity of the fibula. The femur 

 has a third trochanter or process for the insertion of 

 muscles. There are usually twenty -three dorso- lumbar 

 vertebrae. 



As to the dentition, the premolars and molars form a 

 continuous series, with broad transversely ridged crowns, 

 the last premolars often very like the molars. 



The stomach is simple; the caecum is large; there is no 

 gall-bladder. 



The mammas are inguinal; the placenta is diffuse and 

 non-deciduate. 



