LI. Family HELOMYZID^. 



Fig. 130. Leria pubescetis, enlarged. After Washburn. 



Face nearly vertical, or retreating, with oral vibrissas; 

 front bristly on the posterior half only; antennae short. 

 Abdomen rather broad and long, composed of six seg- 

 ments; male genitalia somewhat prominent. Wings com- 

 paratively large; all the basal cells distinct; costa usu- 

 ally bristly; first longitudinal vein bare. Tibiae with 

 spurs and preapical bristle. 



The flies of this rather small family are found in grassy, 

 shady and damp places, on windows, etc. They feed 

 upon decaying animal or vegetable substances, fungi, 

 excrement, etc. Many species live in caves and burrows. 

 The larvae of Lena have been bred from bat and rabbit 

 dung; those of Helomyza from truffles, decaying wood, 

 etc. They are cylindrical, obtuse behind, more pointed 

 in front; the antennae are situated upon long conical pro- 

 cesses; mouth booklets large and pointed: the seven 



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