PSYCHODID.E. 



93 



The members of this famity are often very minute, 

 rarely exceeding the length of four millimeters ; they are 

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



V 



running about on leaves near streams of water, and will 

 be readily recognized by their peculiar moth-like appear- 

 ance; the}- 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. Psyc hod i else, i, Ps ychoda, wing; 2, Pericoma, wing 

 (Eaton); 3, Sycora.v, 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 (Flebotomus!} . . 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. 



ii 



