10 COSTA RICAN DIPTERA 



7. AVings whitish, second section of costal vein glossy black, contrasting 



with the other sections wliich are brownish in color (fig. 9) 



varicosta new species 

 Second section of costa not darker in color than other sections 8 



8. Face, antennae, and legs yellow; mesonotum shining brown black, disk 



of scutellum velvety, opaque black or brown black, .fulva Malloch 

 Species otherwise colored, scutellum never opaque on disk 



9. Last section of second vein equal to basal section of third or very 



slightly longer, the second costal division less than half as long as 



third or barely one-half as long 10 



Last section of second vein distinctly longer than basal section of third, 

 second costal division generally more than half as long as third. . 11 



10. Third vein almost straight on its last section, reaching wing margin at 



very near to apex of wing inconspicu^ new species 



Third vein bent almost rectangularly and reaching margin of wing at 

 very much in front of apex of wing bromeliaruni K. & M. 



11. Small, glossy black species, antennae, legs and wing veins yellow (fig. 6) 



pallicornis new species 



Larger, more or less shining species, legs brown, with yellow joints and 



tarsi and wing veins brown. The face is generally yellowish in 



the paler species when the antennae ai-e of that color and thus there 



is not the striking contrast in color as represented in pallicornis. . 12 



12. Post-humeral bristle present, incurved 21 



Post-humeral bristle absent 13 



13. Scutellum with four marginal bristles 14 



Scutellum with six or eight marginal bristles 20 



14. Very small species, .5 mm. in length; second costal -division very dis- 



tinctly shorter than third minimal new species 



Larger species, 1 mm. or over in length, second costal diviteion as long 

 as, or slightly shorter than third 15 



15. Third vein bent forward on its last section before reaching margin of 



wing; 2 or 3 pairs of dorso-centrals present 16 



Third vein straight or very slightly inclined forward; 1 or 2 pairs of 

 dorso-centrals present 17 



16. Costa stopping at end of third vein, third vein slightly bent forward 



cartagensis new species 



Costa carried distinctly beyond end of third vein; third vein distinctly 



bent forward quadrisetosa new species 



17. Second vein almost rectangularly bent at its apex, the cell enclosed by 



this vein of almost equal width in its entire length 18 



Second vein joining costa at an acute angle, the cell enclosed by it 

 distinctly narrowed apicallj^ 10 



18. Larger species, 2 mm. in length; last abdominal segment in male with 



a long hair-like bristle on either side; legs mostly brown-black 



(fig- 3) rectangularis new species 



Smaller species, 1.5 to 1.75 mm. in Uaigth; last alxlominal segment with 

 the apical iiairs of a more uniform length; legs mostly yellow 



regularis new species 



