418 UNGULATA 
Rhinoceros. Interval between upper incisors less than the width of 
the teeth. Lower incisors slightly notched at the cutting edge. 
Vertebre: C 7, D 22, L 8,8 6,0 6. Of this form the earliest 
known species, H. capensis (Fig. 176) is the type. There are several 
other species, as H. habessinicus and syriacus, from Eastern Africa 
and Syria. They inhabit mountainous and rocky regions, and live 
on the ground. 
Dendrohyraa.1—Molar teeth having the same pattern as Paleo- 
therium (except that the third lower molar has but two lobes). 
Interval between upper incisors exceeding the width of the teeth. 
Lower incisors with very distinctly trilobed crowns. Vertebre : 
C7, D 21,L7,85,C10. The members of this section frequent 
the trunks and large branches of trees, sleeping in holes. There 
are several species, not distinctly defined, from western and south 
Africa, as D. arboreus and D. dorsalis. The members of both groups 
appear to have a power like that possessed by the Lizards called 
Geckos of clinging to vertical surfaces of rocks and trees by the 
soles of their feet. 
It should be added that some writers separate three of the 
African species usually included in Hyrax (viz. H. bocagei, H. bakeri, 
and H. blainvillet) under the designation of Heterohyraz.? 
Suborder PROBOSCIDEA. 
This name has been appropriated to a well-marked group of 
animals, presenting some very anomalous characters, allied in many 
respects to the typical Ungulata, but belonging neither to the Artio- 
dactyle nor Perissodactyle type of that order. It has been thought 
that they possess some, though certainly not very close, affinities 
with the Rodentia, and also with the Sirenia. It is certain, 
however, that the two species of Elephant, which are the sole living 
representatives of the group, stand quite alone among existing 
mammals, differing widely from all others in many points of their 
structure. In some respects, as the skull, proboscis, and dentition, 
they are highly specialised ; but in others, as in the presence of two. 
anterior vene cave and in the structure of the limbs, they retain 
a low or generalised condition. A considerable series of extinct 
forms, extending back through the Pliocene and Miocene epochs, 
show the same type under different modifications, and in still more 
another by George, in Annales des Sciences Naturelles, 6%me sér. tom. i. 1874, in 
which references to all the previous literature will be found. The mechanism 
by which the sole of the foot is enabled to adhere to smooth surfaces is fully 
described by G. E. Dobson, Proc. Zool. Soc. 1876, p. 526. 
’ Gray, Ann, Mag, Nat, Hist. ser. 4, vol. i, p. 48 (1868). 
° See a paper by J. V. Barboza du Bocage, in the Jorn. Set. Phys. Nat. Lisboa 
(2), vol. i. p. 186 (1889), where a list of all the known species will be found. 
