154 DirTERA OF NORTH AMERICA, [PART IV. 



' Discal cell open ; seventli 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 



Knob of the halteres jellow. 5 



Knob of the halteres iufuscated. 1 septemtrionis 0. S. 



^ ) Body and wings yellow or green. 6 



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



^ Cross-veins not infuscated, feet yellow. 7 



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

 ' 3 chrysocoma 0. S. 



(K 



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

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



f 



7-1 

 I yellow. 4 vespertina 0. S. 



^ Whole body pale green or pale yellow. 8 



„ ( Body pale green. 5 chlorophylla 0, S. 



\ Body pale yellow. (5 straminea, n. sp. 



fNo 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, 

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



j 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. 

 -.-. I 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 Sny. 

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



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



,o ( Prevailing color of the body yellow. 13 pubipennis 0. S. 



i Prevailing color of the body brown or black. 14 



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



( Size hardly 0.1 ; color black. 16 ursina 0. S. 



,g ( Antennae altogether brownish, 14 hirtipennis 0. S. 



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



