Xa 64] DIPTERA OF COXNECTICTJT: TAXONOMY 281 



The dorsimacula <!;roup. 



Key to Species 



1. Cells beyond cord of wing darkened, conspicuously variegated by whitish in 



radial cells beyond the stigma 2 



Cells beyond cord of wing uniformly colored, subhyalinc or suffused with 

 yellow or brownish yellow, not with a white post-stigmal area (subiDii- 

 colores) ; compare also atistralis and dietsiana which may in cases be inter- 

 preted as falling under couplet la 11 



2. Wing-apex narrowly but conspicuously darkened, the remainder of disk clear 



or virtually so apical is 



Wing-apex not abruptly darkened and with remainder of surface clear.... 3 



3. Cells basad of cord strongly infumed, cells M to A variegated by whitish 



areas {dorsimacula subgroup) 4 



Cells basad of cord uniformly pale in color 6 



4. Flagellar segments uniformly blackened dorsimacula 



Flagellar segments bicolorous 5 



5. Bases of flagellar segments yellow, the remainder darkened; male hypo- 



pygium with eighth sternite simple .beaulieui 



Bases of flagellar segments brownish black, slightly darker than remainder 

 of segments ; male hypopygium with eighth sternite armed with brushes of 

 setae eriensis 



6. Size large (wing, $ , over 20 mm.) ; {valida subgroup) 7 



Size smaller (wing, $ , less than 18 mm. ) 8 



7. Male hypopygium with a median tuft of long yellow setae on eighth sternite ; 



tergal horns short and inconspicuous hirsuta 



Male hypopygium without a brush of long yellow setae on eighth sternite; 

 tergal horns longer, prominent valida 



8. Antennal flagellum bicolorous ; dark wing-pattern heavier ; a dark spot at 



origin of Rs and darker seams on tn-cn and outer section of Cur, (stib- 



maculata subgroup) 9 



Antennal flagellum uniformly darkened: dark wing-pattern greatly reduced 

 or virtually restricted to the stigmal darkening ; no dark seams at origin 

 of Rs or on m-cu or Ctii ; Subarctic species 10 



9. Male hypopygium with tergal horns short; posterior lobe of inner disti- 



stvle broad, the apex truncated; gonapophyses with apical points not an- 

 gularly bent mallochi 



Male hypopygium with tergal horns (Fig. Zl, I) long and slender; posterior 

 lobe of inner dististyle produced into a slender point or with apex bifid ; 

 gonapophyses with outer ends angularly bent into long slender points.... 



submaculata 



10. Male hypopygium with basistyle produced caudad into a flattened lobe, .loevviana 

 Male hypopygium with basistyle simple penicillata 



11. Cell 1st M-2 open by atrophy of m aperta 



Cell 1st M-2 closed' 1- 



12. Antennae with bases of flagellar segments light yellow, the remainder black 



flavibasis 



Antennae with flagellum, if bicolorous, with bases of segments darker than 

 remainder ^^ 



13. Antennae ($) unusually elongate, if bent backward extending about to the 



fourth abdominal segment; wings (5) uniformly brownish black or dark 



brown ; hypopygium ( $ ) unarmed with lobes or pencils disjuncta 



Antennae shorter, in $ not extending caudad beyond base of abdomen ; wings 

 of both sexes pale, unblackened ; hypopygium ( S ) provided with lobes or 

 hair-pencils ^^ 



14. Male hypopygium with caudal margin of tergite having two rounded emar- 



ginations, one on either side of a double median spinous point (Fig. 32. K) ; 

 8th sternite with median area provided with two parallel-sided sclerotized 



teeth (Fig. 32, A, G, J) (triplex subgroup) • • • • 15 



Male hypopygium without the appearance of two rounded emarginations on 

 caudal margin of tergite; if with a median lobe, this entire (Fig. 32, 

 B, E, M) ; 8th sternite without two submedian sclerotized teeth 17 



