764 MAMMALIA. 



Sub-Order PROBOSCIDEA 



The sub-order is now represented by two species oi 

 elephant (Elcphas), They occupy a somewhat isolated 

 position, though distinctly Ungulates. As regards skull, 

 proboscis, and teeth, they are highly specialised, but their 

 limbs are of a generalised type. 



The elephants are confined to the Ethiopian and Oriental 

 regions. They feed on leaves, young branches, and herbage. 

 By means of the mobile proboscis they gather their food, 

 and they drink by filling the proboscis and then ejecting the 

 water into the mouth. 



The proboscis is a muscular extension of the nose, and 

 bears the nostrils at its tip. The skin is strong, and the 

 hair somewhat scanty. 



In the limbs, radius and ulna, tibia and fibula, are 

 quite distinct ; the radius and ulna are fixed in a crossed 

 position; owing to the length of- the humerus, and yet 

 more of the femur, and the vertical position in which 

 they are carried, elbow and knee are lower than usual, 

 and the gait is peculiar ; the carpal and tarsal bones have 

 flat surfaces; the feet are broad, and bear five hoofed 

 toes embedded in a common integument. There are no 

 clavicles. 



The skull is very large, being adapted to support the 

 proboscis and tusks, and to afford a broad insertion for 

 the large muscles. In most of the bones there is during 

 growth an extraordinary development of air-spaces, which 

 communicate with the nasal passages. The supra-occipital 

 is very large ; the nasal bones are very short ; the zygomatic 

 arch is slender and straight, its anterior part is formed by 

 the maxilla, for the elephant differs from the typical 

 Ungulates in the fact that the jugal merely forms the 

 median part of the zygoma, and does not extend on to the 

 face. The lachrymal is also small, and placed almost 

 entirely within the orbit (cf. the Rabbit). 



The dentition is unique. The two upper incisors or 

 tusks are mainly composed of solid ivory ; the enamel is 

 restricted to the apex, and soon wears off. As the tusks 

 grow, their roots sink through the prem axillae into the 

 maxillae. There are no canines nor premolars. *The 



