DIPTERA. 225 



Frequents damp places, preying upon small insects. Por- 

 phyrops, Chrysotus, Dolichopus, Medeterus. 



Wood-eating flies or Xylophagites. Larva elongate, in- 

 habits decaying wood. Pupa changes in the same situations : 

 in a cocoon. Imago with the antennae ten-jointed ; the basal 

 and second joints are short, moderately robust, and hairy ; 

 the portion corresponding to the apical seta of the Muscina 

 is robust, and composed of eight distinct joints; ligula large, 

 fleshy and pilose ; ocelli three ; wings horizontally covering 

 the body ; alulae none ; hind tarsi often dilated in the males ; 

 body linear, very depressed. Xylophagus, Actina, Beris. 

 Chameleon flies or Stratiomites. Larva very elongate, 

 attenuated at the anterior end, composed of twelve very 

 distinct segments, besides the head; posterior extremity 

 radiated ; inhabits the water. Pupa changes on the surface 

 of the water and continues floating : no material alteration 

 in the form takes place. Imago with the antennae eight- 

 jointed ; the basal and second joints are uniformly robust 

 and hairy ; the ligula is large, fleshy, and bilobed ; ocelli 

 three ; wings narrow, reposing one on the other, and seldom 

 wholly covering the body, which appears on each side ; 

 alulae obsolete ; body very flat, short and wide. Flies in 

 the sunshine, settling on leaves and flowers. Stratiomys, 

 Odontomyia, Oxycera, Nemotelus, Sargus. 



Golden-banded flies or Chrysotoxites. Larva and pupa 

 unknown; the former supposed to feed on the roots of 

 corn, &c. Imago with the antennae six -jointed ; basal and 

 second joints long and slender, third very long and more 

 robust, the remaining three forming a slender and perfectly 

 uniform seta, which arises from near the base of the third ; 

 ligula large, much dilated, bilobed ; wings divaricating, 

 covering the body ; alulae small or obsolete ; body very 

 stout, convex above. Inhabits woods, &c. ; flies briskly in 

 the sunshine. Microdon, Ckrysotoxum. 



Q 



