154 DIPTERA OF NORTH AMERICA. [PART IV. 



3- 



' Discal cell open ; seventh longitudinal vein arcuated in such, a man- 

 ner that the axillary cell is broader in the middle than near the 

 margin (Tab. I, fig. 16). 4 



Discal cell closed ; seventh longitudinal vein straight, diverging from 

 the sixth, and, hence, the axillary cell much broader near the 

 margin than in the middle (Tab. I, fig. 17, 18). 9 



4 ( Knob of the halteres j ellow. 5 



( Knob of the halteres infuscated. 1 septemtrionis 0. S. 



j. ( Body and wings yellow or green. 6 



1 Body and wings brown. 2 villosa 0. S. 



c Cross-veins not infuscated, feet yellow. 7 



6< Cross-veins infuscated, feet conspicuously clothed with black hairs. 

 ' 3 chrysocoma 0. S. 



r Front and humeri with sulphur yellow marks, the remainder of the 

 ,- J head and of the thorax being of a saturated reddish or brownish- 



yellow. 4 vespertina 0. S. 



*- Whole body pale green or pale yellow. 8 



g ( Body pale green. 5 chlorophylla 0. S. 



I Body pale yellow. 6 straminea, n. sp. 



No stump of a vein inside of the discal cell; femora with brown 

 bands. 10 



A stump of a vein inside of the discal cell (Tab. I, fig. 18) ; femora 

 ^ without brown bands. 10 armata 0. S. 



r "Wings with a broad brown band and a large brown spot before it, 

 , ft j nearer the basis (Tab. I, fig. 17). 7 venusta 0. S. 



i Wings with a very narrow brown band and numerous brown spots 

 ** and marks. 11 



r Prevailing color of the body and of the wings yellowish. 

 y. j 8 armillaris, n. sp. 



i Prevailing color of the body and of the wings brownish. 

 ^ 9 graphica 0. S. 



/Wings brownish, with numerous white spots. 11 caloptera Say. 

 12 -J Wings pale grayish, with small dark spots along the margin, at the 



' tip of the longitudinal veins. 12 parva 0. S. 



■jo ( Prevailing color of the body yellow. 13 pubipennis 0. S. 



( Prevailing color of the body brown or black. 14 



, . ( Size from 0.2 to 0.25 ; color brown. 15 



I Size hardly 0.1 ; color black. 16 ursina O. S. 



- - ( Antennse altogether brownish. 14 hirtipennis O. S. 



\ Two basal joints of the antennae yellowish. 15 forcipula, n. sp. 



