RELATIONSHIPS. 45 



IX. The N. Somali Elephant (E. a. orleansi), on the other Central 

 hand, is smal^ with the upper border of the small ears straight, 



and the lappet short and distinctly denned. 



X. In the West Sudan Elephant (E. a. rothschildi) the ears are 

 in some respects intermediate between those of the Abyssinian 

 and those of the West African race, although approximating to 

 the former in the shape of the lappet. 



There is also a dwarf elephant from the Congo (E. a.pumilio). 

 The Albert Nyanza Elephant has been separated as E. a. albert- 

 ensis, and is characterised by the unusually short and broad 

 skull. 



RELATIONSHIPS OF THE PROBOSCIDEA. 



The discovery of the Eocene Proboscidea proves that, although 

 the elephants are no doubt rightly included among the Ungu- 

 lata or hoofed -animals, they are at the same time very widely 

 separated from the other members of that group, or at least 

 from the existing members of it, and seem to have formed an 

 independent series from the earliest Tertiary times, when they 

 probably arose from some quite generalised form of the primitive 

 group called the Condylarthra. A very early side-branch from 

 the Proboscidean stem is probably represented by the Sirenia 

 or Sea-cows, aquatic animals which, though now as unlike 

 elephants as possible, still possess a number of anatomical 

 peculiarities in common with them, so that this relationship 

 was recognised long ago. Recently a number of Sirenians have 

 been found in the Eocene strata of Egypt (pier-case 30), one Flor- 

 in the same horizon as Moeritherium. These early Sirenians caseji 

 are much less specialised than the existing forms, having 

 the full series of teeth and a complete pelvis, and probably a 

 functional hind limb. In many points they resemble Moeri- 

 therium, as for instance in the form of the brain, teeth, and 

 pelvis ; and it seems likely that both they and Moeritherium 

 had a common ancestor in Lower Eocene times. It was pro- 

 bably a swamp-living creature, some of whose descendants 

 became gradually more and more exclusively aquatic in their 

 habits, thus giving rise to the Sireuia, while others became 



