218 DIPTERA. 



DIPTERA APHANIPTERA. 

 FAMILY I. Puliddce. 



Parasitic insects, with scale-like rudiments of wings ; legs long, 

 especially the hind legs, which are formed for leaping, and provided 

 with very large coxse ; larva vermiform. 



The fleas are too well known to need description. A variety 

 of species, very similar in appearance and habits, have been de- 

 scribed as infesting various animals and birds. The eggs are laid 

 in the dust, where the larvae are said to feed on congealed blood, 

 feathers, or other particles of animal matter which they find near 

 them. But, like some other parasitic animals, they are able to 

 accommodate themselves to a variety of food, and, in warm coun- 

 tries, colonies of fleas are often met with in sandy places living on 

 the bare ground. Some light has, however, been thrown upon 

 this subject by the recent discovery that fleas will attack cater- 

 pillars (and doubtless other insects also), and suck their blood. 

 When they cannot meet with vertebrate food, it is clear that they 

 will attack any other animal which may happen to fall in their way. 



A second genus of this family (Sarcopsylla, Westw.) contains the 

 Jigger or Chigoe (S. Penetmns, Linn.), which burrows into the skin 

 of men and animals in the West Indies and South America, where 

 the body of the gravid female swells to the size of a pea, and a 

 most dangerous wound is produced if the creature is not carefully 

 removed intact. 



The Pulicidce were formerly treated as a distinct Order under 

 the name of Aphaniptem (Invisible Wings), so called from the 

 rudimentary wings with which they are provided. They are 

 now, however, generally regarded as a slightly aberrant family of 

 Diptera. Platypsylla Castoris, Ritsema, the type of Westwood's Order 

 Achreioptera, a beaver parasite resembling a small flattened cock- 

 roach, and alluded to on p. 1 2 as possibly belonging to the Diptera, 

 is now referred by the best Coleopterists to the Coleoptera, and is 

 considered to be related to the Silphidce. 



DIPTERA NEMOCERA. 



Oviparous, two-winged flies ; antennae composed of more than 

 six joints; palpi with four or five joints. 



The arrangement of this and the following groups is chiefly 

 taken from Osten-Sacken's Catalogue of the Diptera of North America, 

 2d ed., and Schiner's Diptera Austriaca. 



