The True Flies 



of the body is usually metallic greenish or the antennal 

 style is usually apical, antennae sometimes composed of 

 more than three joints ; head of the larva of a firm 

 texture and definite shape, pupa not inclosed in the old 

 larval skin, or if inclosed this never forms a hard, cylindrical 

 puparium, the pupa or the imago issuing through a longi- 

 tudinal and transverse fissure (Section Orthorhapha). • 2 



Discal cell, when present, never furnished with more than two 

 veins; never more than three posterior cells are present, 

 the third vein never forked; when the second basal cell is 

 confluent with the discal the color of the body is never 

 metallic green; antennae never more than three-jointed, 

 the terminal joint usually furnished with a slender arista 

 which is generally dorsal, empodium bristle-like or want- 

 ing ; head of the larva soft and mobile except the mandi- 

 bles, the pupa inclosed in the hardened skin of the larva, 

 which is ruptured circularly near the anterior end during 

 the emergence of the imago (Section Cy dor kapha) . . .50 



Section ORTHORHAPHA Brauer. 



2 — Joints of antennas more than three in number; the last one 

 seldom furnished with a slender style or arista; antennae 

 and legs usually very long and slender; body also 

 usually slender, and rather delicate (Subsection Nemo- 

 cera) 3 



Joints of antennae never more than three in number; the ter- 

 minal one much longer than the others and frequently 

 annulate, sometimes furnished with a jointed style or 

 arista; antennae and legs usually short and robust; body 

 often elongated (Subsection Brachycera) 15 



Subsection NEMOCERA Latr, 



3 — Antennae usually long and slender, the joints usually longer 

 than broad, and nearly always provided with verticels of 

 bristly hairs, the structure frequently very different in the 

 opposite sexes of the same species; eyes seldom broadly 

 contiguous above the antennae in either sex, sometimes 

 narrowly contiguous above and below the antennae, the 

 facets of a uniform size and not separated by a transverse 

 line into an upper and a lower portion; body usually 

 slender and elongate, pulvilli wanting (Super-family 



Tipnloidea) 4 



84 



