300 DIPTERA OF NORTH AMERICA. [PART II. 



Walker, Insecta Saundersiana. 

 Page 207. Psilopus lepidus Mas. 



Yiridis, .abdominis segmentorum marginibus anticis nigris, 

 antennis pedibusque nigris, alis limpidis fusco-bifasciatis. 



Bright-green, beset with black bristles ; head blue, tinged with 

 purple, adorned in front with white bloom ; eyes bright-red ; 

 mouth black ; feelers black ; sixth joint as long as the chest ; 

 chest not shining, tinged with blue ; breast with a hoary covering ; 

 abdomen tapering from the base to the tip, narrower and much 

 longer than the chest ; a black band on the fore border of each 

 segment ; legs black, clothed with black hairs and bristles ; wings 

 colorless, adorned with two dark-brown bands which are united 

 on the fore border ; tip cross-vein forming a right angle, whence 

 it is indistinctly waving to the tip of the wing ; lower cross-vein 

 very slightly waving ; wing-ribs and veins black. Length of the 

 body two and one-half lines ; of the wings six lines. 



Mexico. 



Page 211. Medeterus exustus Fem. 



Nigro-aeneus, capite antico viridi ; abdomine purpureo cupreo, 

 antennis pedibusque nigris, femoribus seneis, alis cinereis, costa 

 venarumque marginibus fuscis. 



Allied to M. notatus. Bronze-black, beset with black bristles, 

 which form a cross-row behind the head, adorned beneath with a 

 whitish covering ; head green in front, clothed beneath with black 

 hairs ; peristoma prominent ; eyes red ; facets of the fore part 

 rather large ; feelers black ; abdomen obconical, coppery with a 

 slight purplish tinge, not longer than the chest ; legs long, black, 

 thickly clothed with black down, beset with a few black bristles ; 

 thighs brassy, armed with black spines ; foot-cushions dark-tawny ; 

 wings darkish-gray, very dark-brown beneath the fore border and 

 along the borders of the veins in the disk ; wing-ribs and veins 

 black; poisers dark-tawny with pitchy knobs. Length of the 

 body two and one-half lines ; of the wings six lines. 



Bolton, North America, 



