56^ CHORD ATA. 



The feet are plantigrade, but the toes have become 

 reduced in number : there are four on the front foot and 

 three behind, the third (middle) being the largest. The 

 carpals and tarsals are serial, as in Condylarthra. The 

 fibula is complete and has acquired an articulation with 

 the astragalus. 



The stomach is slightly constricted into two chambers 

 and there is a fairly large caecum. There are also two, 

 peculiar, paired, conical caeca attached to the large intestine, 

 which are not known to occur in any other mammals. The 

 placenta is said to be zonary and deciduate. Hyrax 

 inhabits rocky grounds and extends from Syria to Cape 

 Colony ; in the latter place it is known as the " dasse," or 

 " klip das," in the former as the daman. Dendrohyrax is 

 arboreal and is found in East Africa. 



The recent discovery of Pliohyrax in the Lower Pliocene 

 of Europe (Samos) has added yet more interest to these 

 extraordinary little animals. Pliohyrax, known only by the 

 skull, was larger than Hyrax and more generalised. Thus, 

 in addition to the large median incisors there were also 

 two smaller ones and a canine the latter in shape resembling 

 a premolar. Hence, in the upper jaw at least, the dentition 

 was 3.1.4.3. The premolars differed somewhat from the 

 molars. Judging by the peculiar position of the anterior 

 and posterior nares and the orbits, Pliohyrax was probably 

 amphibious, if not completely aquatic. As already indi- 

 cated, the Hyracoidea are probably an offshoot from a 

 condylarthrous type which have retained many primitive 

 characters. 



SUB-ORDER III. — PROBOSCIDEA. 



The elephants differ from the other Ungulata so much 

 that they have to be placed at the least in a sub-order apart. 

 The most important anatomical characters are these : — 

 The nose produced into a long proboscis or trunk; one pair 

 of upper incisors forming long tusks ; molar and premolar 

 teeth large and polylophodont, showing horizontal succes- 

 sion; fibula and ulna complete; the carpals and tarsals serial 

 and five toes present; placenta zonary and non-deciduate 

 and mammae pectoral. 



