iS ENfOMOI^OGICAL NEWS [Jan., '15 



2 Femora black, the tips may be yellow 3 



Femora yellow or mostly yellow 54 



3 Wings with dark markings 4 



Wings without dark markings 35 



4 Dark markings on the wings consist of two cross-bands connected 



along the costa, in some immature specimens reduced to an in- 



f uscation of the veins 9 



Dark markings otherwise 5 



5 Wings black except beyond the forking of the fourth vein and 



the hind margin. (Ariz., Mex., W. T., S. Am.) . .dimidiatus Loew 

 Wings mostly hyaline 6 



6 Wings with an ill-defined brownish band extending from the costa 



to the posterior end of the cross-vein. (Mex.) . . .infumatus Aid. 

 Wings with a cloud along the anterior portion 7 



7 Middle tibiae with rather large bristles on the front surface 8 



Middle tibiae destitute of bristles. (Mex.) ciliipennis Aid. 



8 Middle tibiae with three long, slender bristles, hind tibiae without 



bristles. (Pa.) chalybeus V. D. 



Middle tibiae with a row of about fourteen bristles, hind tibiae 

 with a similar row. (Mex., Cent. Am.) cilipes Aid. 



9 Fore tarsi with dense black fringe on the sides of the fourth and 



fifth joints, middle tarsi with the second and third joints less 



broadly fringed. (Mex.) bifimbriatus Aid. 



Fore tarsi of different structure 10 



ID Fore tibiae black 11 



Fore tibiae pale, at utmost brownish 14 



11 Second antennal joint with many and long bristles 12 



Second antennal joint with few and short bristles. (Mex.) 



praestans Aid. 



12 Last four joints of fore tarsi subequal 13 



These joints of gradually decreasing length. (West U. S., Mex.) 



melampus Loew 



13 Face with numerous delicate, pale hairs. (U. S.) . . patibulatus Say 

 Face bare. (West U. S.) pilicornis Aid. 



14 Fore tarsi yellow, not or but little infuscated towards the tips.. 15 

 Fore tarsi infuscated, part of the first joint may be yellow 17 



15 Abdomen with two long, wavy, hair-like bristles on the sides at 



tip. (Mex., Guatemala.) forcipatus Aid. 



Abdomen without such bristles 16 



16 Middle tarsi black, fourth and fifth joints with narrow silvery 



fringe above. (Mex., Brazil.) diffusus Wied. 



Middle tarsi but little infuscated and with the fourth joint pure 

 white. ( W. L, Mex., Brazil.) bellulus Aid. 



