XVII. FAMILY CYRTID^E. 



Fig. 66. 



Opsebius pterodontinus, enlarged. After Lugger. 



Small to large, never elongate, pilose or nearly bare 

 flies. Head small or very small, formed chiefly by the 

 large eyes, which are usually contiguous in both sexes 

 above or below, or above and below the antennae; three, 

 two or no ocelli present ; antennae composed of two or 

 three joints, with or without a terminal arista or bristle. 

 Proboscis rudimentary or long, sometimes very long. 

 Thorax large, spherical; squamae very large and inflated; 

 scutellum large. Abdomen closely united to the thorax, 

 large and inflated. Legs rather stout; the tarsi with 

 three membranous pads under the claws. Venation 

 variable, the veins sometimes weak and indistinct; often 

 a supernumerary cross-vein between the third and fourth 

 veins. 



This family, the Cyrtidae or Acroceridae, comprises a 

 small number of curious flies with curious habits. They 



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