708 MAMMALIA [CH. 



loose in a room across which numerous strings have been stretched, 

 will fly about without touching one. Owing to their powers of flight 

 Bats are exceedingly widely distributed and extend to small oceanic 

 islands where there are no other Mammals. The true Blood-sucking 

 Bat or Vampire, Desmodus rufus, is found in Central and in South 

 America. Its back teeth are rudimentary, but its front teeth are 

 razor-edged. Pteropus, which includes the so-called Flying Foxes or 

 Fox-bats of India and Madagascar, belongs to the family PTEROPIDAE; 

 these are the largest Bats known; they feed exclusively on fruit, and 

 the cusps on their teeth are blunter than is usual amongst Bats. 

 The African Xantkarpyia> one species of which frequents the 

 interior of the Pyramids and other dark ruins in Egypt (Fig. 357) 

 belongs to the same family. In Great Britain there are some fifteen 

 species of Bat divided amongst five genera. Of these the Long-eared 

 Bat, Plecotus auritus ; the Whiskered Bat, Vespertilio mystacinus ; 

 the Horse-shoe Bats, Rhinolophus Mpposiderus and R. ferrumequi- 

 numj the Barbastelle, Synotus barbastellus ; and the Pipistrelle, 

 Vesperugo pipistrellus ; represent the genera. Besides the species 

 just mentioned there are three more species of Vesperugo and three 

 more of Vespertilio in Britain. South America has a large fauna 

 of peculiar Bats, but the North American forms are allied to the 

 British, although the species are distinct. The Serotine, Vesperugo 

 serotinus, is the only species common to the two regions. Scotophilus 

 humeralis is one of the most familiar species peculiar to North 

 America. 



Order X. Primates. 



The last order of the Mammalia is that of the Primates, which 

 includes Lemurs, Monkeys and Man. As was mentioned before, this 

 order is characteristically arboreal, that is to say most of its members 

 live among trees, climbing from branch to branch. This circum- 

 stance may explain why they retain certain primitive characteristics 

 found elsewhere only amongst the Insectivora. Thus the thigh and 

 upper arm are quite free from the body and the whole sole and palm 

 are placed on the ground when walking; and there are five fingers 

 and five toes. On the other hand the eyes are pushed round to the 

 front of the skull instead of being placed at the sides of the head, 

 and the jugal joins the postorbital process of the frontal, so that 

 the orbit is surrounded by a bony ring (Fig. 358). Some at least 

 of the toes have flat nails. The big toe is shorter than the rest, 



