G4 DITTERA OF NORTH AMERICA. [PART II. 



Green, rather shining. Antennae red ; third joint somewhat 

 longer than the two first taken together, of rather equal breadth ; 

 arista distinctly pubescent. Front bright bluish-green. Cilia 

 of the inferior orbit whitish. Humeri of the same color as the 

 remainder of the upper surface of the thorax. Upper side of the 

 abdomen more golden green ; the whitish pubescence on its sides 

 occupies more space than usual. Lamellae of the hypopygium of 

 the ordinary size and rather rounded in shape, white, with a rather 

 narrow black border along the upper and apical edge ; the latter 

 jagged and fringed with black bristles. Coxae and feet pale yel- 

 lowish ; anterior side of the fore coxae only with a very delicate 

 whitish pubescence ; middle coxae with a blackish spot on their 

 outside. Hind femora with a bristle before the tip and sparsely 

 ciliated with long yellowish-white hairs on the latter half of their 

 under side. Hind tibiae of ordinary thickness, on their hind side 

 only with a very short glabrous stripe near the basis. Fore tarsi 

 more than once and a half the length of the tibiae, slender ; the four 

 first joints stalk-like, yellowish ; the two first joints, taken together, 

 are somewhat longer than the tibia ; the joints diminishing in 

 length and stoutness from the first to the third ; the fourth joint 

 is equal to about one-third of the length of the third and is only 

 slightly stouter than the latter ; the fifth joint is black, as long as 

 the fourth, somewhat flattened and bearded on its upper side with 

 dense, somewhat incumbent, short, black hairs. Wings rather 

 yellowish-gray, somewhat narrowed near the basis ; the fourth 

 longitudinal vein not broken ; costa only slightly thickened at the 

 tip of the first longitudinal vein. 



Ilab. Middle States. (Osten-Sacken.) 



Observation. — If in determining a female specimen, this species 

 is hit upon, and if its wings, instead of being yellowish gray, are 

 distinctly gray, then it will be necessary to compare what has 

 been said about such females in the observation to the twenty- 

 first species. 



B. Humeral callosity yellowish. 



33. D. scapula ris Loew. % and 9 . — Viridis, humeris flavis, facie 

 albidii, antennis rufis, oculorum ciliis inferioribus albidis, ciliis tegula- 

 rum nigris, pedibus flavis, tarsis maris simplicibus, alarum vena longi- 

 tudinali quarta non fracta. 



Green with yellowish humeri ; face whitish ; antenna? red ; cilia of the 



