466 



THE STUDY OF INSECTS. 



The venation of the wings is represented by Figure 568. 

 Vein III is four-branched ; cells V I and V, are both obliter- 

 ated by the coalescence of the veins that bound them ; cell 

 VIII is closed at a considerable distance before the margin ; 

 and the 2d cell III is much longer than cell V. 



The larvae, which are sometimes found in dwellings 



viia+ix 



Fig. 568.— Wing of Scenopinus. 



under carpets or in furniture, are very slender, and are re- 

 markable for the apparently large number of the segments 

 of the body, each of the abdominal segments except the last 

 being divided by a strong constriction. They are also found 

 in decaying wood, and are supposed to be carnivorous. 



The family is a very small one. The most common 

 species is Scenopinus fenestralis (Sce-nop'i-nus fen-es-tra'lis). 



Family Empidid^: (Em-pid'i-dae). 

 The Dance-flies. 



The dance-flies are of medium or small size ; they are 

 often seen in swarms under trees or near shrubs and about 

 brooks, dancing and hunting. The family is a rather diffi- 

 cult one to characterize owing to great variations in the 

 form of the antennae and in the venation of the wings. 



The branches of vein VII coalesce with the adjacent 

 veins (VII, with V 3 and VII 2 with IX) from the margin of 

 the wing towards the base for a considerable distance (Fig. 

 569). In most of the genera this coalescence is carried so 

 far that the free parts of the branches of vein VII appear 



