574 Syrphidae. 



part of the eye black; sometimes the whole lower side part black ; 

 vertex with black, behind with yellow hairs, frons with black or brown 

 hairs; epistonia with pale hairs. Jowls varying from orange to black. 

 Occiput whitish grey pruinose, the hairs whitish below, yellow above, 

 somewhat long. Eyes with short, whitish hairs. Antennæ black, third 



Fig. 195. Antenna of C. festivuni d", from the inside. X 40. 



joint much shorter than tlie two basal joints together, and all three 

 joints of nearly equal length^; arista about of the length of the third 

 joint, brownish yellow on the basal part. Thorax black, shining, with 

 two grey stripes, abbreviated behind the middle and a little diverging; 

 it has the usual yellow longitudinal side spots from humeri to the 

 transverse furrow, and on the postalar calli and produced forwards; 

 they are not widely interrupted; thorax is clothed with somewhat 

 long, brownish hairs. Scutellum yellow with a smaller or larger black 

 spot on the disc; it has brown hairs with more or fewer black on 

 the middle. Pleura with the usual three yellow spots somewhat large 

 and distinct; the hairs are yellow. Abdomen black, dull, somewhat 

 shining at the hind margins of the segments, along the middle line 

 and at the apex; it has four pairs of bright yellow, equal and rather 

 arched bows, not reaching the side margin ; the third, fourth and fifth 

 segments have pale hind margins, the margin is narrow on the third 

 segment and often not reaching the sides or present only in the 

 middle; the margin on fifth segment is the broadest; abdomen is 

 clothed with very short hairs which quite folio w the ground colour; 

 just along or beneath the side margin they are a little longer, brownish 

 yellow, and they are long and all yellow on and about the basal 

 corners. Genitaha small, black and black-haired. Venter black, shining. 



1 Generally the second Joint is given as a little shorter than the first; my measure- 

 ments show, however, that when dissociated these joints are equal in length, 

 but in situ the second is a little shorter as its base is overlapped by the first 

 joint. 



