270 Annals Entomological Society of America [Vol. VI, 



Generic Characters of Agromyza. 



Hea4 of normal size; frons broad, from one- third to a little 

 over one-half the head width ; ocelli on a slightly raised portion ; 

 the ocellar triangle, so distinct in the Oscinidce, seldom trace- 

 able; orbits distinct, 3-5 pairs of orbital bristles present anterior 

 to front ocellus; one pair of bristles on ocellar region slightly 

 behind anterior ocellus, pointing forward and slightly diver- 

 gent, vertical row consisting of two central divergent and 

 two outer convergent bristles; postvertical bristles divergent; 

 face nearly straight in vertical outline, or slightly concave, 

 slightly keeled in center, or unkeeled; mouth margin not pro- 

 duced; antennas of moderate size, or third joint enlarged, 

 but never elongate or produced at apex; second joint with at 

 least one dorsal setula; arista bare or pubescent, never plumose; 

 cheeks linear or broadened posteriorly, sometimes one-half 

 as high as eye, bristles confined to margin, vibrissa generally 

 noticeably differentiated ; proboscis membraneous, not elongated 

 noticeably nor geniculate; palpi normal. Mesonotum with 

 2-4 pairs of dorso-centrals ; mesopleurce with 1-3 long posterior 

 bristles as well as generally a number of setulas; one or two 

 bristles above mid coxae and generally numerous setulae; 

 propleural bristle strong; squamae distinct. Ovipositor of 

 female generally with base chitinized, apex seldom protruding; 

 male hypopygium of moderate size, not incurved. Legs 

 without preapical bristle on dorsal surface; end spurs weak. 

 Wings with subcostal v^in weak, sometimes incomplete, but 

 generally complete and ending very near to first vein, or 

 fused with first at near apex; costa at end of subcosta uninter- 

 rupted, or only slightly so; costal vein with very short hairs 

 which are, with exception of two slightly more distinct at 

 end of subcosta, of almost equal length to beyond middle 

 of wing; cross veins near to wing base, or the outer one 

 at, or slightly beyond, wing middle; posterior basal cell always 

 complete though small; anal vein (sixth) distinct; costa to 

 third vein, slightly beyond it, or to fourth. This last char- 

 acter is difficult to distinguish sometimes, and is not of suffi- 

 cient importance to permit of the relegation of those species 

 having costa to only third vein, to a different genus from 

 those with costa to fourth. 



