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Family Ephydridae — The Shore Flies 



Ochthera humilis. 



Small to very small flies, the anal cell absent, the second basal and 

 diseal cells united. 



Face more or less, often rc'marka])ly convex, the oral cavity 

 rounded, sometimes very large; clypeus distinct but often retracted 

 within the oral cavit.y; no distinct oral vibrissa but the sides of the 

 face often with bristles or hairs. Antennae short; arista bare, pubescent 

 or pectinate, always dorsal. Thorax gently convex, bristled. Legs 

 short; tibioe without preapical bristle, the middle pair with apical spur. 

 Wings rarely aborted; auxiliary vein united with the first vein except 

 basally; costa broken before the tip of the first vein and weakened 

 beyond the humeral crossvein; second basal and diseal cells united; 

 anal cell absent or extremely small and incomplete. Abdomen com- 

 posed of six segments in the males, seven in the females, the number 

 sometimes apparently reduced to three, variable but never elongate, 

 often quite wide; genitalia usually retracted; body usually with but 

 few hairs. 



The adults are found in moist places, inhabiting marshes, SAvamps 

 and the shores of lakes, ponds, and streams, along the edges of brooks 

 and the sea shore. Many of the species are of local habitat but most of 

 them are widely distributed. Some si)ecies occur in the flowers of 

 water plants and have been found nowhere else. Water lilies arc usually 

 frequented by several species while in bloom and many occur on the 



