OBSERVATIONS. 



I have seen but two specimens, which are 

 both males, taken near Philadelphia. In form 

 of body it resembles the S. scalaris, Fabr., and 

 tseniatus, Meig., of Europe. 



The upper figure of the plate. 



SYRPHUS OBSCURUS. 



SPECIFIC CHARACTER. 



Blackish-green; tergum with lateral full cu- 

 preous triangles. 



DESCRIPTION. 



Male. Head metallic black, tinged with 

 green : antennse, third joint dull testaceous : 

 stethidium entirely blackish-green, polished, im- 

 maculate: feet dull testaceous, thighs blackish 

 at base : tergum velvet-black, slightly tinged 

 with green ; second segment with a dull coppery 

 semioval spot on the middle of the lateral mar- 



PLATE XI. 



