238 INSECTA SAUNDERSTANA. 
base : the black triangles in the disk of the abdomen much smaller than 
those of the male. 
Length of the body 24 lines; of the wings 5 lines. 
Var. 8. Black colour in the third and fourth segments much more 
prevalent. 
United States. 
SYRPHUS INTERROGANS, Fem. 
Al neus, capite antico thoracis lateridus scutelloque fulvis, abdomine nigro 
fasciis fulvis ornato apice eneo, antennis pedibusque fulvis, femoribus 
tibiisque posticis piceo cinctis, alis sublimpidis. 
Head metallic green, purple on the crown, tawny in front and on the 
sides above the feelers, tinged with hoary, and clothed with white hairs be- 
hind and beneath: chest and breast bronzed ; sides of the chest and hind 
border of the scutcheon tawny ; a short yellow band on each side of the 
breast: abdomen black, nearly spindle-shaped, much longer but not 
broader than the chest, adorned with four irregular tawny bands, the first at 
the base ; hind border of the second forming four curves, its disk adorned 
with four P-shaped black marks; third like the second, but its hind 
part is still more enlarged ; fourth small, interrupted in the middle ; tip 
bronzed, hind borders of its segments tawny: legs tawny; feet darker; a 
pitchy band near the tip of each hind-thigh ; two indistinct pitchy bands on 
each hind-shank ; hind-feet pitchy: wings nearly colourless ; wing-ribs 
tawny ; veins black, tawny at the base; poisers tawny. Length of the 
body 2% lines; of the wings 5 lines. 
North America. 
Syrenus Barua, Fem. 
Aineo-viridis, abdomine fusco suturis nigris, pedibus fulvis posticis pi- 
eis, alis subcinereis. 
Brassy green: head bluish green, brassy on the crown; a pale yellow 
stripe widening in front along each side of the face ; hind-head tinged with 
gray, clothed with hoary hairs: sides of the chest and hind-border of the 
scutcheon somewhat pitchy ; a yellow band on each side of the breast : ab- 
domen brown, spindle-shaped, with a slight brassy tinge, much longer than 
the chest, sometimes bronzed with pitchy sides; sutures of the segments 
