1913] Agromyza and Cerodontha. 273 



30. Halteres pale yellow, with a black spot on outer side of knob; dorso-central 



bristles strong, anterior pairs almost as sti"ong as posterior pairs; last 



section of fifth vein shorter than penultimate section 



27 maculosa, new species. 

 Halteres without any dark spot on knob 31 



31. Outer cross vein at about the length of inner cross vein from that vein; third 



and fourth veins very distinctly divergent at apices 



28 waltoni, new species. 



Outer cross vein separated by a greater distance than inner cross vein from 



that vein; third and fourth veins slightly divergent at aoices 32 



32. Small species, at most 2 mm., base of wing, including basal half of first vein, 



upper part of pleurae and mesopleural vertical suture narrowly, a small 

 patch below base of .wing, stjuamas, and fringe lemon yellow; general 

 color shining black; outer cross vein below, or at very slightly beyond 



end of first vein 29 angulata Loew. 



Species other than above in color, etc 33 



33. Larger species, 3 mm. and over, almost entirely black-browTi ; lower half of 



orbits rather closely set with hairs 30 setosa Loew. 



Smaller species, about 2 mm., not so uniformly colored; lower half of orbits 

 sparsely haired 34 



34. Rather robust species; wings broad; cheeks linear; tibiae and tarsi yellowish. 



31 isolata, new species. 

 More slender species- wings narrow; cheeks one-fourth as high posteriorly as 



height of eyes; tioiae and tarsi barely paler than femora 



32 fragaricB, new species. 



35. Species with three distinct pairs of dorso-central bristles 36 



Species with 2 distinct parts of dorso-central bristles 39 



36. Glossy black species; base of wing, squamae and small portion of pleurae pale 



lemon yellow; frons not one- third the width of head; anterior pair of 

 dorso-central bristles strong; arista as long as from its base to anterior 

 ocellus; frontal lunule yellowish, distinctly white pollinose; male with 



apical segments of abdomen conspicuously pale yellow 



' 33 posticata Meigen 



Apex of abdomen in male not yellow; frontal lunule not yellow, not noticeably 



white pollinose 37 



37. Smaller species, less than 2 mm. in length 38 



Larger species, over 2 mm. in length 36 dubitata, new species. 



38. Last section of fifth vein distinctly shorter than penultimate sectioii 



34 neptis Loew. 



Last section of fifth vein distinctly longer than penultimate section 



35 inco7ispicua, new species. 



39. Abdomen black, without any metallic sheen; antennae brownish; aristae 



distinctly pubescent 37 parvicornis Loew. 



Abdomen black, with a metallic, bluish, or greenish sheen; antennas black; 



arista never distinctly pubescent 38 viridida Coquillett. 



" 40. Costa to end of third vein .* 41 



Costa to end of fourth vein 43 



41. Arista short, not more than three times as long as breadth of third antennal 



joint, distinctly pubescent; outer cross vein at its own length from inner 



cross vein; three pairs of dorso-central bristles on mesonotum 



39 salicis, new species. 

 Arista bare; mesonotum with two pairs of dprso-centrals 42 



42. Cheeks very short, not higher posteriorly than anteriorly, and about one- 



sixth as high as eye; antennae of moderate size; arista about three times as 



long as width of third joint 40 winnemance, new species. 



Cheeks long, distinctly higher posteriorly than anteriorly, at highest part 

 at least one-third as high as eye; antennas rather small, arista about 

 six times as long as width of third joint 41 simplex Loew. 



