XXxii, '21] ENTOMOLOGICAL NF.YVS 201 



A Key to the Species of the Genus Coenosia Meigen 

 (Dipt., Anthomyiidae). 



By J. R. MALLOCH. 



The species included in this key fall within the limits of the 

 genus as restricted in several of my recent papers on the family. 



Key to species. 



1. Legs either entirely yellow or with only a portion of the coxae or 



tarsi or both blackened 2 



- Legs with at least a portion of one or more pairs of the femora, in 



addition to the tarsi, blackened 17 



2. Abdomen of male short and broad, segments two and three much 



narrowed laterally, with a large glossy black patch on apex of for- 

 mer and base of latter on each side; dorsum of abdomen in both 

 sexes with central vitta and paired spots; third antennal segment 

 black; legs usually entirely reddish yellow; anal angle of wing in 

 male usually produced thumblike orata Stein 



- Abdomen of male not as above, segments two and three not conspicu- 



ously narrowed laterally; species not as alxtve in other respects. . . .3 



3. Third antennal segment entirely pale yellow 4 



Third antennal segment largely or entirely black or brown 10 



4. Head including antennae and proboscis yellow ; thorax yellow, with 



or without a grayish or blackish dorsocentral vitta and a similarly 

 colored mark on center of metanotum modestn Loew 



- Thorax largely or entirely black, and usually at least a part of an- 



tennae or proboscis black or brown 5 



5. Abdomen unspotted, more or less broadly yellow at base in male and 



with dense white or pale gray pruinescence ; thorax with dense 

 white or pale gray pruinescence, entirely unmarked: antennae short. 

 about two-thirds as long as face ni: ca Loew 



- Abdomen with paired dorsal spots 6 



6. Antennae entirely yellow; abdomen broadly yellow at base, sometimes 



entirely yellow, with large, paired dorsal brown spots, fifth sternite 

 yellow, with long slender processes at the base of the inner margins 

 of which there are some black setulae ; interfrontalia largely red- 

 dish anteriorly; hind tibia with the antcrodorsal bristle very strong 

 and of moderate length, the antero ventral one weak, situated much 

 nearer to apex of tibia <;;;/. -;nM//.s- Stein 



- Antennae with at least the second -eminent largely or entirely black- 



ened 7 



7. Anterodorsal and preapical dorsal bristles on hind tibia excessively 



long and slender, usually three-fourths as long as the tibia; antero 

 dorsal bristle on mid tibia half as long as tibia, the posterodorsal 

 one much shorter laiii/ispinosti Malloeli 



- Anterodorsal and preapical dorsal bristle- mi bind tibia not ball' as 



long as tibia, or the antermlorsal bristle on mid tibia is shorter than 

 the posterodorsal one N 



