36 Bulletin of the Brooklyn Entomological Society Vol. XII 



3. Mesonotum with 4 pairs of postsutural dorso-central bristles, ■ 



Tetramerinx. 

 — . Mesonotum with at most 3 pairs of postsutural dorso-central bristles 4. 



4. Arista with very long plumosity; abdomen in male with 5 dorsal seg- 



ments visible Pentacricia. 



— . Arista short-haired, pubescent, or bare ; abdomen in male with 4 dorsal 

 segments visible 5- 



5. Frons much produced beyond anterior margin in eye, usually from one 



third to one half the length of eye; arista pubescent, much thickened 

 on basal half; face receding towards mouth; last abdominal segment 



in female armed with chitinised hooks Phyllogaster. 



— . Frons very slightly produced beyond anterior margin of eye; arista 

 slender except at extreme base ; face almost vertical in profile ; last 

 abdominal segment in female not armed with chitinised hooks . . 6. 



6. Squamae small, subequal; male with large ventral subapical append- 



ages Hoplogaster. 



— . Squamae rather large, under scale much larger than upper . .Coenosia. 



I consider that the minute distinctions between Coenosia, 

 Caricea, Dexiopsis and Limnospila are not sufficiently constant 

 nor are they so evident that they can be depended upon as char- 

 acters for the differentiation of genera. I therefore place all 

 species of these so-called genera in Ca:nosia. 



Neochirosia gen. nov. — Generic characters : slender, closely resembling 

 Chirosia in habitus. Eyes widely separated in both sexes, cruciate frontal 

 bristles absent; orbital bristles long; antennae shorter than face, third joint 

 but little longer than second, rounded apically; arista almost bare, slender, 

 swollen at immediate base; cheeks rather high, bristly on lower margin; 

 proboscis fleshy. Anterior supra-alar bristle distinct, almost one third as 

 long as posterior one; 4 pairs of postsutural dorso-centrals present ; sterno- 

 pleural bristles in an almost equilateral triangle. Abdomen slender, sub- 

 cylindrical; basal segment distinct but short; hypopygium small, the ven- 

 tral recurved processes chitinised, last ventral segment with a deep 

 V-shaped central incision. Legs slender, strongly bristled; claws and 

 pulvilli subequal in length. Sixth vein of wings complete, seventh extend- 

 ing almost to margin. 



Neochirosia setiger sp. n. — Male and female : length 5 mm. ; black, cov- 

 ered with slight but distinct pruinescence. Head with distinct silky yel- 

 lowish white pile; palpi black; antennae black. Thorax not vittate, slightly 

 shining. Abdomen colored as thorax, without distinct markings. Legs 

 black, tibiae and tarsi yellowish testaceous. Squamae gray. Halteres yel- 

 low. Wings slightly brownish, especially anteriorly. 



Orbits exceeding anterior margin of eye about as far as width of third 

 antennal joint; cheek about half as high as eye, the latter almost exactly 

 circular in outline. Acrostichals 2-rowed ; scutellum with a very long pair 



