LEPTID.^. 



159 



not very active in their habits. The larger species are 

 commonly found in meadows and woodlands, resting 

 upon stems or trunks of trees with their head downward. 



*' 



\ 



Fig. 52. Ccenomyiaferruginea, female; enlarged. 



They are sometimes predaceous upon other insects, and 

 the species of Symphoromyia have a habit of sucking 

 blood as do the horseflies. The larvae are predaceous, 

 living in the earth, in decaying wood or in passages 

 made by woodboring beetles. Others live in moss, in 

 sand cr in water. In general they are cylindrical, with 

 or without fleshy abdominal legs. The last segment has 

 a transverse cleft, the portion above which is provided 

 with two, often backward-bent points or processes; the 

 under part is obtuse, with the two stigmata between them. 



