DIPTERA. 351 



Then comes Syrphidae, in which the fore-part of the head, a little 

 above the superior margin of the oral cavity, or near the origin of 

 the snout, presents a prominence. 



At the beginning of these species we will place those whose an- 

 tennae, always shorter than the head, are furnished with a plumous 

 seta. 



Their body is short, and frequently pilose, and the wings are dis- 

 tant. At the first glance these Insects resemble Bombi, and as the 

 larvae of several inhabit the nest of those Hymenoptera, it seems as if 

 the Author of nature clothed them in a similar manner, in order that 

 they might penetrate into their habitations without danger. 



The Syrphidae compose three subgenera. 



VoLUCELLA, Geoff., Lat.,3Ie{g., Fab., 



Where the third joint of the antennae or the palette is oblong; its 



contour forms a curvilinear and elongated triangle. 



V. mystacea; Musca mystacea, L.; V. bourdon, De Geer, In- 

 sect. VI. viii, 2. Black, and densely pilose ; thorax and extre- 

 mity of the abdomen covered with fulvous hairs ; origin of the 

 wings fulvous. 



The larva inhabits the nests of Bombi. Its body is widened 

 from before posteriorly, is transversely rugose, has little points 

 on the sides, six membranous radiating threads at the posterior 

 extremity, and presents above, two stigmata and six pairs of 

 mammillae, each furnished with three long hooks, which enable it 

 to crawl. Here also comes the 



M. a zones, Geoff. ; Syrphus inanis, Fab.; Panz., Faun. In- 

 sect. Germ., II, 6. Eight lines long ; but slightly pilose ; ful- 

 vous. ; head yellow ; two black bands on the abdomen. Its 

 larvae also lives in the nest of the Bombi *. 



Sericomtia, Meig., Lat. — Syrphus, Fab., 

 Where the palette of the antennae is semi-orbicular f . 



Eristalis, Meig., Fab., 

 Which (restricting the subgenus to those species where the seta of 

 the antennae is evidently hairy) only differs from Sericomyia in the 

 wings. Here the exterior and closed cell of the posterior margin, 

 that which is situated near the angle of the summit, has a deep 

 rounded emargination in the external side ; in the preceding subge- 

 nus it is straight J. 



To these succeed other subgenera very analogous by the short 

 form of the body, the triangular abdomen and by the antennae, much 

 shorter than the head, but where the seta is simple or without very 

 apparent hairs. 



In some, as in Eristalis, the external margin of the last external 



* For the other species, see Lat., Meig., and Fallen. 



t The same authors. 



J The E. intricarius, similis, alpinus, Meig. 



