380 THE FOREST-FLY AND SHEEP-TICK. 



objects of, or peculiarly sensitive to, its attacks. 

 Another common species is tlie Stenopteryx Hirun- 

 dinis, whicli infests the Swallow, and is distinguished 

 by its peculiarly elongated, narrow and pointed wings. 

 Both this and the preceding species will occasionally 

 attack man, and people who have picked up a bird 

 which has just stunned himself under the irritation 

 caused by these tormentors are frequently bitten by 

 them. The Forest Fly {Hippobosca equina), another 

 winged species, is abundant in the New Forest, where 

 it is one of the greatest torments to horses, usually 

 fixing itself under the belly, and irritating the animals 

 sometimes to such an extent, that their riders have 

 some difficulty either in keeping their seat or dis- 

 mounting in safety. 



The Melophagus ovinus, or Sheep-Tick, is a very 

 spider-like apterous species, found commonly upon 

 the sheep, and is remarkable for the large size of its 

 abdomen. But the most singular of the wingless 

 forms are the curious little NycteribicB, or Bat-lice, 

 which are found only upon different species of Bats, 

 and which have the head turned backwards upon the 

 thorax, so that at the first glance they appear to 

 have their bodies, as in the spiders, divided only into 

 two portions, and their resemblance to some of the 

 Arachnida is greatly increased by their long, stout 

 legs, attached to the sides of the thorax. 



I 



