SYRPHIDAE OF MAIN' 1C. 245 



"Abdomen with more isolated and much more undulating bands, 

 especially as regards the fore-margins of the bands on the third and 

 fourth segments ; the spots on the second segment are either isolated 

 or only reach the side-margins at the upper corners, while the bands 

 on the third and fourth segments do not quite reach the side margins 

 and are beautifully undulated especially on the fore-margin; the hind 

 margins of the fourth and fifth segments are less broadly orange; 

 apparently the belly also gives a good distinction as S. nitcns has 

 isolated central black spots on the second, third, and fourth segments, 

 while S. nitidicollis has only the hind margins of the third and fourth 

 segments black; a very important character occurs in the marginal 

 pubescence, which is all black after the basal corners, proving that 

 normally the abdominal yellow bands do not reach the side margins 

 and thereby thoroughly distinguishing it from S. nitidicollis." 



"Legs quite distinct, as the basal two-fifths of the anterior femora 

 and the basal four-fifths of the hind femora are black; the anterior 

 tarsi have the three middle joints darkened, while the hind tarsi are 

 usually more blackish. Pubescence behind the anterior femora almost 

 all black." 



"Wings less orange hued, the whole wing and especially the front 

 part being more smoky." 



"$. Similar to the male, but also differing from 5\ nitidicollis by the 

 undulating abdominal bands, darker antennae, and flatter more ovate 

 shape. Vertex brilliant purple, which is extended forwards down the 

 middle of the frons for a short distance, which is more obvious when 

 viewed from in front but which leaves the front half of the frons 

 much more yellowish than in S. nitidicollis; the dark spots or streaks 

 above the antennae are small and sometimes inconspicuous ; the mouth- 

 edge is usually black, but there is only a trace of the middle facial 

 line." 



"Thorax brilliantly shining." 



"Abdomen more ovate than in 5". nitidicollis, with the basal pair of 

 spots less sharply triangular, while the undulating bands are broader 

 and may just indistinctly touch the side-margins at their upper cor- 

 ners, though not enough to cause pale marginal pubescence ; the peculiar 

 ventral spots seem very much as in the male." 



"Legs paler than in the male, as in the original specimen upon which 

 the specie* was introduced as British they are entirely orange down to 

 the base of the femora, but usually the basal fifth of the anterior, and 

 the basal two-fifths of the hind, femora are black; tarsi as in the male." 



"Wings rather more orange than in the male Length 



about 10.5 mm Rare." 



In the Maine males the face across the knob with a black stripe, 

 abbreviated much short of the base of the antennne, prominent in all 

 except one specimen. This stripe is continuous with the narrow black 

 margin of the anterior mouth-edge. The latter black stripes turned 

 obliquely outward toward the eye. cutting off a small, triangular, yel- 

 lowish spot next the month edge before the jowls which are again all 



