XXXli. '21] ENTOMOLOGICAL NEWS 107 



i '( psta continued to apex of fourth wing-vein 5 



5. Hind tibia with three median bristles, posterodorsal, anter odor sal, 



and anteroventral, the two former very long, the last sometimes 



weak or absent 6 



Hind tibia without the long posterodorsal bristle, sometimes with 

 one or two setulae 7 



6. Abdomen in male short and broad, fifth sternite with short pro- 



cesses which are frequently covered by the fourth tergite ; fore 

 tibia without an anterodorsal bristle in both sexes, the mid femur 

 with a series of strong bristles on anterior surface, which does not 



extend much beyond middle Ncode.riopsis Malloch 



Abdomen in male elongate, narrow, fifth sternite with large processes 

 which are always conspicuously exposed ; fore tibia with an antero- 

 dorsal bristle in both sexes, the mid femur with a series of widely 

 placed strong bristles on anterior surface, the outer one about one- 

 fourth from apex Macrocoenosia Malloch 



7. Hind tibia without an anteroventral bristle ; abdomen in male short 



and stout, sometimes with two bare glossy areas on each side ; 

 fore femur in both sexes with short setulae on entire length of 

 anteroventral surface ; ocellar bristles very short and weak, 



Xenocoenosia Malloch 



Hind tibia with an anteroventral bristle ; fore femur without short 

 setulae on anteroventral surface, or the ocellar bristles long and 

 strong 8 



8. Hind tibia with two strong, long bristles at middle, one on the 



anterodorsal and the other on the anterior surface, their bases 

 very close together, almost contiguous ; hind tarsus usually with a 

 setula near base of ventral surface of basal segment, 



Caricea Robineau-Desvoidy 



Hind tibia with an anteroventral and an anterodorsal bristle which 

 are not nearly contiguous at bases ; hind tarsus usually without a 

 setula at base on ventral surface of basal segment, 



Coenosia Meigen 



9. Frons longer than broad, its sides parallel, or slightly divergent 



anteriorly Hoplogastcr Rondani 



Frons broader than long, its sides convergent anteriorly, 



Schoenomysa Haliday 



Of the genera included in this key there are t\v<> which havr 

 not been previously listed by me. Bithoracochaeta and .Itlicri- 

 gona. The former is represented in North America by leuco- 

 procta Weidemann, (antic a Walker, insn/nis Su-in), and the 

 latter by varia Meigen. The specimen of Athcrit/ono varia on 

 which 1 base the inclusion of the genus in our list was taken 

 by Mr. Charles Robertson at Inverness. Florida. 



