284 BRITISH MAMMALS 



exception of bristles (often bifid) round the muzzle, and a few 

 at the end of the tail. The mammae are reduced to one pair. 



Hippopotamuses appear to have originated, like so many 

 other remarkable beasts, in India, and they arose, seemingly, from 

 an early Artiodactyle family (allied to the pigs) called the Anthra- 

 cotherida, the teeth of which, in some forms, bear a strong 

 resemblance to those of the hippopotamus. The earliest known 

 forms of Asiatic hippopotamus had six incisor teeth in both jaws. 

 This type with the six incisor teeth penetrated westwards as far 

 as North Africa, and possibly the south of Europe. From this 

 type there arose in the later Pliocene a hippopotamus with only 

 four incisor teeth in each jaw. This form was identical with 

 the modern African hippopotamus, and reached England in the 

 Pleistocene Epoch, before the Glacial episodes or during the 

 warmer intervals between the Ice ages. It penetrated at least as 

 far north as Yorkshire (possibly during the summer-time), and 

 was coeval with the earliest types of man in Britain. In fact, 

 there were hippopotamuses in the Thames once, larger than those 

 in the Nile at the present day, but not specifically diff^erent. No 

 doubt it frequented all the English and some of the Welsh rivers 

 south of Lancashire and Durham. It may have swum the 

 narrow straits of the Irish sea, and have reached Antrim. On 

 the coast of this county remains of the hippopotamus are said to 

 have been found, but they are of a dubious nature, and until 

 better evidence is forthcoming the hippopotamus cannot be 

 classed as an Irish mammal. 



Family: SUIDAi, THE TRUE PIGS 

 The True Pigs, like the hippopotamus, appear to have been 

 confined at all times to the Old World, and never to have existed 

 in America, where they are only distantly represented by the 

 allied group of the Peccaries, and by certain ancestral forms from 

 which both pigs and peccaries sprang. Pigs made their appearance 

 very early in Europe in the Upper Miocene formations, and it 

 is possible that they originated in Central Europe, though they 

 soon travelled to Asia, and in India received some wonderful 



