388 Syrphidae. 



laid in spring and the final developnient taking place in spring 

 next year. 



The species of Brachyopa are of a characteristic exterior among 

 the Syrphids as they are rather Hke to Muscids, especially to Scato- 

 pJiaga or to some species of Phaonia (Aricia), but I should not think 

 that this has anything to do with mimicry. They occur on ulcerative 

 stems and trunks and may also be found flying in low herbage. 



Of the restricted genus Brachyopa 4 species occur in the palæ- 

 arctic region, and of Hatmnerschmidtia 3 species, thus in all 7; two 

 have been found in Denmark, both belonging to Brachyopa s. str. 



Table of Species. 



1, Thorax with disc and pleura grey; abdomen all yellow .... 1. bicolor. 

 — Thorax with the disc more or less, sometimes slightly, yellow, 



pleura yellow ; abdomen with dark base and incisures 2. dorsata. 



1. B. bicolor Fall. 



1817. Fall. Dipt. Suec. Syrph. 33, 2 (RJiingia). — 1822. Meig. Syst. 

 Beschr. III, 262, 2, Tab. XXX, Fig. 6. — 1843. Zett. Dipt. Scand. II, 690, 5 

 et 1859. XIII, 5087,5. — 1862. Schin. F. A. I, 327. — 1901. Verr. Brit. 

 FL VIII, 475, 1, figs. 333—335. — 1907. Kat. palåarkt. Dipt. III, 87. 



Male. Vertex black, greyish or brownish anteriorly; frons and 

 epistoma yellowish red, whitish pruinose, especially epistoma. Vertex 

 black-haired, frons and epistoma without hairs, the latter only with 

 some few just at the oral side margin; epistoma hollowed below 

 the antennæ and the lower part considerably produced and a little 

 descending. Occiput grey, the lower part and the jowls more or less 

 ferruginous; the hairs are whitish. Antennæ yellowish red, the third 

 joint short oval; arista short-pubescent. Thorax slate-grey, almost 

 dull, with four darker, a little more shining stripes; the two middle 

 stripes approximated, united in front, a little diverging behind and 

 here abbreviated, the lateral abbreviated in front and interrupted at 

 the transverse furrow ; the humeri sometimes more or less reddish 

 and likewise the postalar calli. Thorax clothed with short, rather 

 dense, blackish hairs; there are as a rule some black, bristly hairs 

 above the wing-root and on the postalar calli. Scutellum brownish 

 red or more or less darkened in the basal part, likewise with dense, 

 blackish hairs, and with some bristles or bristly hairs at the margin. 

 Pleura grey with a little longer, whitish hairs; at the upper hind 

 corner of mesopleura usually a couple of black, bristly hairs. Abdomen 

 short, broadest a little behind the base and narrowing rapidly towards 

 the end; it is yellow or yellowish red, sometimes a httle darkened 



