AitT. y FLIES OF THE FAMILY SYRPHIDAE SHANNON 19 



about three times as long as broad; eyes large, the loAver margins 

 bordering onto oral margins; dorsum of thorax smaller than head, 

 frontal aspect; thorax black pilose; legs black, with black pile, the 

 terminal tarsal joints all yellowish ; hind tibia rather slender, with a 

 very faint dorsal incision, moderately pilose ; hind tarsus thickened ; 

 abdomen shining black with three visible segments; the third more 

 than half the abdominal length, with the sides deflected downward 

 so that the abdomen tapers toward the apex; hypopygium small; 

 wings infuscated with a white crossband just beyond middle; halteres 

 black, squamae reduced, black ciliated. Length, 6 mm. ; wing, 5 mm. 



Two males. 



Tyfe locality.— Amn^zoYL (1866, H. W. Bates). 



Type. — In British Museum. 



This species closely resembles Trigona lacteipennis Friese. 



MICRODON (UBRISTES) TRIGONIFORMIS. new species 



Male. — Similar to Iacteipe7i7iis, but the first antennal joint is equal 

 to the third; the wings are uniformly infuscated; hind tibia much 

 larger and with a distinct dorsal incision beyond middle; four 

 abdominal segments present, the fourth nearly as long as the basal 

 three ; angle in the apical cross vein a little more than a right angle, 

 the distal portion directed somewhat inward; abdomen with four 

 visible tergites, greatly narrowed behind the second segment owing 

 to the turning downward and under of the sides of the third and 

 fourth segments; fourth tergite as long as the combined length 

 of the second and third (measured along median line) ; squamae re- 

 duced, blackish ; halteres blackish. Length, 7.5 mm. ; wing, 5.5 mm. 



One male. 



Type locality. — Villa Nova, Brazil (H. W. Bates). 



Type. — In British Museum. 



MICRODON (UBRISTES) GOETTEI, new sp«cies 



Female. — General color brownish yellow with dark markings. 

 Front a little broader than long, upper three-fourths inflated; an- 

 tennae yellowish brown, slightly longer than fore tibia, first joint 

 nearly three times as long as broad, the second about one-fourth 

 length of first, third a little longer than combined length of first and 

 second; arista as long as first; face nearly parallel sided, about twice 

 as long as broad; fore and mid legs yellowish, hind legs darker, 

 hind tibia as in trigoniformis] abdomen with sides behind second 

 tergite but little turned under (probablj^ distinctly so in the male) ; 

 wings subhyaline, a broad whitish preapical band present ; dorsum of 

 thorax reddish brown, the disc blackish. Length, 9.5 mm.; wing, 

 7 mm. 



Five females. 



