DIPTERA. 265 



d d. Third feeler-joint about four times the length of the second ; sixth 



downy, 

 addita. 

 c c c c c c. Praebrachial vein forming a slightly obtuse angle at its 



flexure. 



d. Third feeler-joint about twice the length of the second. 



atriventris. 

 dd! Third feeler-joint near twice the length of the second. 



umbrosa, dubia. 

 d d d. Third feeler-joint six times the length of the second. 



e. Facialia beset with bristles. 



adusta. 

 e e. Facialia without bristles. 



alia. 

 c c c c c c c. Praibraehial vein forming an obtuse angle at its flexure. 



d. Third feeler-joint full twice the length of the second. 



picea, umbrifera, com pacta. 

 d d. Third feeler-joint thrice the length of the second. 



e. Facialia without bristles. 



interrupta, e bconica . (i^\AJrirzuvi.A 1 ^4 

 ee. Facialia bristly. 



chrysotelus. 

 dd. Third feeler-joint four times the length of the second. 



subpicea. 

 cccccccc. PrEebrachial vein forming a very obtuse angle at its flexure. 

 (/. Sixth feeler-joint bare. 

 e. Third feeler-joint about twice the length of the second. 



sordida, siibaurata. 

 e e. Third feeler-joint not less than thrice the length of the second, 



antennata, aucilla. 

 eee. Third feeler-joint not less than four times the length of the second. 



obconicci, vulgata, tricincta. 

 d d. Sixth feeler-joint pubescent. 

 e. Third feeler-joint much more than twice the kngtli of the second. 



vittata. 

 ee. Third feeler-joint thrice the length of the second. 



tencbrifera, scita. 

 ece. Third feeler-joint four times the length of the second. 



