MAMMALS. 163 



properly come, therefore, within the scope of the present 

 chapter. On the other hand, tapirs and rhinoceroses, as 

 dating from the lower part of the Miocene or the upper 

 portion of the Eocene period, might be considered to claim 

 notice in our survey, while the same remark would apply 

 to the civets of the genus Viverra. Since, however, these 

 mammalian types are comparatively well represented at 

 the present day, they scarcely come under the designation 

 of "living fossils." There is, however, one mammal to 

 which this title is strictly applicable, namely, the water- 

 chevrotain of Western Africa. This genus of mammals 

 was originally made known to science upon the evidence 

 of fossil remains from the Pliocene rocks of Darmstadt 

 described under the name of Dorcatherium in 1836. Four 

 years later, a living ungulate from West Africa was 

 described as a species of musk-deer (Moschus), and the 

 same creature was in 1845 made the type of a new 

 genus, Hyomoschus. Subsequently other extinct species 

 of Dorcatherium were described from the Miocene rocks 

 of Europe and the Pliocene of India, and it was eventually 

 proved that the African water-chevrotain belonged to the 

 same genus as these reputedly extinct forms. Hence, the 

 animal in question, as being the sole existing representa- 

 tive of a genus which had formerly a comparatively wide 

 distribution and which was originally described as extinct, 

 has the most indisputable claim to rank as a "living 

 fossil." 



M2 



