SYNOPSIS OF NORTH AMERICAN SYRPHIDiE. 7 



linear, subequal to the third, testaceous at base. Thorax bronze black, 

 obsoletely cupreous liueate, clothed with yellowish pile. Scutellum 

 greenish black, white pilose, rather plane, with the apex emarginate 

 and armed on each side with a minute tooth of the same color. Abdo- 

 men oblong-ovate, punctulate, black, the penultimate segment subequal 

 to the two preceding together, with the base and lateral margins yel- 

 low pilose, and with the pile on the disk so arranged that a broadly 

 interrupted fascia ou the posterior margin of the third segment, two 

 large separated spots on the fourth segment, two smaller subcontiguous 

 ones on the fifth segment, clothed with white pile, are apparent. Ven- 

 ter yellow pilose, black piceous, with the posterior margin of each seg- 

 ment dilutely yellowish. Legs black piceous, base of femora, knees 

 and basal half of hind tibiae dilutely testaceous ; tarsi neither dilated 

 nor incrassate. Wings cinereous, clouds of the transverse veins nar- 

 rowly blackish, posterior angle of the first posterior and discal cells 

 rounded, not appendiculate. — Translation. 



There is a considerable variation among the specimens which I have 

 examined, and while, from an examination of the types in the Loew col- 

 lection, I do not believe them specifically different, I deem it best to here 

 give their descriptions. 



^ , 9 . Length, 7 to lO"'"". Head metallic, shining green; face nearly 

 parallel in profile with the border of the eyes, clothed with yellowish- 

 white pile. Front, in the male, with a distinct transverse groove, in 

 width a little less than the distance from the ocelli to the base of the 

 anteunse, clothed with light-yellow pile ; in the female the front is of 

 the same width as the face, and the transverse depression is less distinct. 

 Antennse black, the first joint reddish at the base, third joint obtuse 

 at tip, not as long as the first joint. Dorsum of thorax in the male 

 shining brassy green, with an indistinct median stripe ; in the female, 

 more greenish blue ; clothed with moderately long and abundant whitish 

 pile. Scutellum gently convex, with an acute spine on each posterior 

 angle: pile of the same color as on the dorsum of the thorax, a little 

 longer and more abundant. Tegulse white, with white pile on the mar- 

 gin. Abdomen more than twice as long as wide, bluish green, moder- 

 ately shining, clothed with yellowish-white pile, which forms an indis- 

 tinct, interrupted, transverse cross-band on the posterior part of the 

 third segment, and two oblique spots on the fourth segment. Legs 

 black ; the tibise clothed with white pile ; posterior metatarsi not quite 

 as long as the remaining joints together, but little or not at all dilated. 

 Wings only lightly tinged with blackish ; the outer posterior angles of 

 the first posterior and discal cells strongly convex. 



Var. rujicrus, new. — A single male specimen from Connecticut seems 

 to show a specific variation from the foregoing, but as one specimen is 

 insufficient to decide it, I will here give the differences. The face is 

 rather more projecting in profile below; across the front there is some 



