256 DIPTEKA OR TRUE FLIES. 



flattish in form, with a hard leathery skin, deep brown in 

 colour with paler mottlings ; the head is dull yellowish except 

 on the face, where it has a dark stripe ; the thorax has a pale 

 spot on the scutellum, and yellowish-grey markings along the 

 sides and posterior part ; the abdomen is bristly, brown above, 

 paler brown to grey below ; the two wings are opaque, longer 

 than the abdomen, and have thick brown veins along the costal 

 region ; the legs are long and bristly, tawny yellow in colour, 

 and banded with brown. The foot is remarkable, and consists 

 of a pair of large claws, with an appendage on each, outside ; 

 there is also a long bristle-like thread coming out beneath the 

 clav;s, and a curious flap -like process between. These flies 

 use their wings but weakly, only flying on the horse and from 

 part to part of the same animal. They cling to the hairs and 

 run about, pulling the hair, and cause much irritation by so 

 doing as well as by blood - sucking. Like all Pupipara, "the 

 Forest Fly deposits round puparia, which are notched at one 

 end. There is but one larva in the female, which lives there 

 until the puparial skin is formed, when the puparium is laid, 

 the larva inside soon turning to a pupa. In four weeks the fly 

 emerges from this case. Animals soon get used to their presence, 

 but a strange horse will become most restive when they settle 

 upon it, especially when (as often happens) the belly is attacked. 

 Little can be done to keep them oflf, except sponging the horse 

 over with a paraffin sponge. 



Two other species are sometimes troublesome — namely, the 

 Fowl-fly {Orniflumiijia avirularia) and the Bee-louse {Braula 

 cii'ra) ; the former a winged species that attacks birds, the latter 

 a wingless reddish-brown insect parasitic on the hive-bee. 



Several others {H. maculafa, H. rutipex, Sec.) attack animals 

 in warm climates. 



Aphaniptera or Fleas (Pulicidse). 



Several species of fleas are found in Great Britain, all partial 

 parasites, living upon man, animals, and birds. Fleas are 



