THE PIGMY HIPPOPOTAMUS. 



In spite of the progress which has been made 

 in the study of natural history during the past 

 thirty years there still remain a considerable 

 number of interesting animals which continue to 

 be rare and obscure, although they have long been 

 known to science. Thus the colocollo— a hand- 

 some tiger-cat — was for many years only known 

 from a single skin ; the Derbian eland, though 

 discovered in 1846, is even to-day numbered 

 amongst the rarest of antelopes ; our knowledge 

 of the West Indian seal is not only fragmentary, but 

 out of date : and only two examples of Brannick's 

 paca — practically a huge guinea-pig — have been 

 seen since the type specimen was taken in Peru 

 nearly thirty years ago.^ 



The name hippopotamus, like that of whale or 

 elephant, is usually applied to mammalia of great 

 size, such as the living Hippopotamus amphibiiis 

 of Africa, or the long-extinct H. major, of Britain. 

 Even the casual visitor to a zoological garden 

 retains a vivid impression of the common African 

 species as a monster silently swimming round its 

 tank, submerging itself without a ripple to rise 

 again with the same remarkable noiselessness ; or 



1 Tlie two additional specimens of Brannick's paca were not taken 

 till 1904. 



