ochraceous: thorax blackish, two gray oblong- 

 triangular spots on the anterior margin, connect- 

 ed with a lateral line that extends nearly to the 

 origin of the wings : poiser and scale whitish : 

 pleura and pectus silver-gray : feet ochraceous ; 

 posterior thighs much dilated, with a very dis- 

 tinct rufous spot each side, and another at base, 

 posterior half of the inferior edge more promi- 

 nent, spines extending from near the base to the 

 tip ; posterior tibia blackish, rufous in the middle 

 and at base : tergum black ; first segment with 

 an ochraceous lateral margin and basal edge; 

 second segment with a large semioval ochraceous 

 spot each side ; third segment with a small trans- 

 versely semioblong-oval ochraceous spot each side 

 at base; fourth segment with a transverse pale 

 ochraceous line each side at base, and posterior 

 margin : venter yellowish-white, blackish at tip. 



OBSERVATIONS. 



Very common in the neighbourhood of Phila- 

 delphia, on flowers. I obtained a variety in 

 Virginia, of which the spots of the tergum are 

 grayish-glaucous. The two sexes are similar in 

 colour. 



It is closely allied to Syrphus pipiens of Fabri- 



PLATE VIII. 



