Syrphidae of Maine. 175 



and ventrad, which meet across the tip in a moderate emargination between 

 the two stigmal plates which are only a very little divergent. 



The slit-like spiracles are a little elevated on carinae, are almost ex- 

 actly straight in surface view, and about equi-distant and equally diver- 

 gent from each other. 



The interspiracular ornanientation consists of short, sharp, elevated 

 irregular ridges, or carinae, (instead of nodules), much more elevated than 

 the spiracles ; hardly at all continued down the sid'es of the tube ; pale 

 brown in the larva, black during the pupal sta^e. 



Puparium (Fig. 12, F, G). Average length 7.2 mm., height 3.5 mm., 

 width 3.8 mm. 



"These puparia (Fig. 12, G) are exceptionally inflated dorsally, the 

 ratio of height to length being greater than in any of the other species I 

 have examined. It is characteristic of them also that the posterior inflation 

 is equal to, or greater than, that anteriorly; in outline, as seen from the 

 side, the dorsal half of the puparium makes an almost perfect semi-circle," 

 reaching its greatest height a little in front of the middle. "The ventral 

 line is sinuate. The respiratory appendage (a) projects from the lower 

 posterior part. From above, the outline is sub-ovoid, broadest in front of 

 the middle, thence narrowing gradually to the posterior third ; whence the 

 puparium is strongly and unevenly compressed to the tip of the respiratory 

 appendage. 



"Color at first grayish brown, sometimes marked with oblique patches 

 of black; posterior breathing appendage darker. As the pupa approaches 

 metamorphosis the anterior end darkens to deep reddish-brown in the re- 

 gion of the eyes ; while on the posterior half, the three principal, yellow 

 abdominal bands of the adult become visible through the transparent 

 wall." Color of the empty puparium light testaceous brown. 



"The segmental spines remain, as in the larva, very inconspicuous. 

 The posterior breathing appendage also retains its characteristics." 



The larvae from Ash developed as follows : 

 One pupated July 16th, 

 One " July 19th, emerged July 30. 

 Two " July 20th, " July 30. 



Three " July 24th, " Aug. 1. 



The duration in this stage under laboratory conditions was therefore 

 from eight to eleven days. The pupation record for the Ohio specimens 

 was seven to eight days. 



Ad III I (Fig. 12, H, I). Shannon's description is as follows: 



"Squamae with rather long, light yellow pile ; ground color of the sides 



of thorax bright yellow, with yellow pile; bands on the third and fourth 



abdominal segments entire and extending over the margins almost in their 



full width. 



"Male : Frons yellow with bluish green reflection, a black spot above 

 each antenna, and with fine rather long, black hairs wliich continue a 

 short distance down between the antennae and eyes. First two antennal 

 joints reddish-brown, the third joint darker, reddish beneath and some- 



