PSYCHODID^B. 



93 



The members of this family are often very minute, 

 rarely exceeding the length of four millimeters ; they are 

 observed in shady places, on windows, in outhouses, or 

 running about on leaves near streams of water, and will 

 be readily recognized by their peculiar moth-like appear- 

 ance ; they run about nimbly, but their flight is weak. 

 The larvae live in rotting vegetable material, in dung, or 

 in water; they are peculiar in having both open spira- 

 cles and tracheal gills; the maxillae are imperfectly de- 

 veloped, there are eye-spots on the head, and the segments 

 behind the head are without feet, but are provided with 

 sucking disks, in the aquatic forms at least. 



Fig. 26. Psy c hod id se. 1, Psychoda, wing; 2, Pericoma, wing 

 (Eaton); 3, Sycorax, wing (Eaton); 4, Trichomyia, wing (Eaton). 



TABLE OF GENERA. 



1. Two simple longitudinal veins between the forked veins. . 2 

 One simple longitudinal vein between the forked veins. . 4 



2. The first simple vein arises from the forked vein much beyond the 



anterior cross-vein {Flebotomits!) . . Phlebotomus. 

 The first simple vein arises near anterior cross- vein. . . 3 



3. The second simple vein ends at or near tip of wing (1) . Psychoda 

 The second simple vein ends distinctly beyond tip of wing (2). 



Pericoma. 



4. The seventh longitudinal vein (the most posterior one) not much 



shorter than the sixth (4) Trichomyia. 



The seventh longitudinal vein very short (3). . Sycorax. 



11 



