THE CANADIAN ENTOMOLOGIST 9 



SYNOPSES OF THE ANTHOMYIID GENERA MYD^A, OPHYRA, 

 PHYLLOGASTER, TETRAMERINX, AND EULIMONOPHORA 



(DIPTERA). 



BY J. R. MALLOCH, 

 Urbana, 111. 



The genus MydcBci as here Hmited is essentially northern in its distribution, 

 most of the species being found in the extreme northeast and northwest, with 

 a few occurring as far south as Texas, though rarely. Stein lists about 300 

 species in this genus, but very few indeed of the species so listed really belong 

 to the genus as I have discovered by examining a great number of the species 

 involved. Most of the species he lists as belonging to this genus from North 

 America belong to Helina. The other genera dealt with in this paper have but 

 few representatives in this country, and two of them, Tetramerinx and Phyllo- 

 gaster, are unknown from the old world. 



Mydaea Robineau-Desvoidy 



This genus is distinguished from its allies by having the third wing-vein 



setulose at base, fourth not curved forward at apex, hind tibia without calcar, 



penultimate abdominal sternite in female with a number of short bristles, eyes 



of male subcontiguous, prealar bristle present, prosternum bare, face not buccate. 



Key to Species. 



MALES. 



1. Legs largely or entirely black; knobs of hal teres black or brown except in 



calvicritra 2 . 



Legs with the exception of the tarsi, and sometimes part of the fore femora, 

 yellowish testaceous; knobs of halteres pale 4. 



2. Eyes with dense hairs; halteres pale yellow calvicriira Coquillett. 



Eyes bare; halteres black or brown 3. 



3. Arista with the longest hairs as long as width of third antennal segment; 



wings slightly infuscated throughout ohsciira Stein. 



Arista with the longest hairs not longer than its basal diameter; wings 

 slightly brownish, the bases of veins orange yellow rugia Walker. 



4. Scutellum largely or entirely yellow, contrasting sharply with the colour 



of disc of thorax 5. 



Scutellum coloured as disc of thorax 7. 



5. Palpi yellow, antennae almost Entirely so fiavicornis Coquillett. 



Palpi black, antenna; almost entirely so 6 



6. Hind femur without bristles on postero ventral surface except at extreme 



apex occidentaUs Malloch. 



Hind femur with a series of long, line, rather closely placed bristles on 

 apical half of posteroventral surface pagana Fabricius. 



7. Antennae entirely black; longest hairs on arista at least as long as width 



of third antennal segment; fore femora infuscated except in 



discimana 8. 



Second antennal segment brownish yellow; longest hairs on arista not as 

 long as width of third antennal segment; claws of fore tarsus not as 

 long as apical tarsal segment; fore femora yeWow... per similis Malloch. 



January, 1921 



