260 SYBPHID^J. 



transverse veins of the middle, and a paler and more diffuse brown spot 

 on the disc near the tip. Alulae whitish. Halteres yellow. Abdomen 

 clothed in the middle part with whitish hairs, at the tip with black 

 hairs, and with tawny hairs towards the base, where there is a tawny 

 spot on each side ; all the hairs pale tawny. Femora tawny at the base ; 

 anterior tibiae ferruginous ; tarsi black, ferruginous towards the base. 

 Not common. (E.) 



Genus XIII. VOLUCELIrA. 



VoLUCELLA,Gf.i.(1776); Mir.; Shr.f. b.; Ll.;Mg.; St. F.etSrv.; Ct. ; 

 Mq. ; Ztt. ; Edn. Musca, L. ; Dg. ; Fb. ; Schlb. ; Shr. i. a. ; Gm. ; 

 Hbst. Syrphus, Fb. ; Pz. ; Fin. 



Antennae articulo quarto dorsali, sexto plumoso. Alee areola subapicali 



Integra, lobo axillari distincto, venis subcostali et radiali ante marginem 



conjunctis. Halteres conspicui. 



Body broad. Head almost semicircular, somewhat contracted in 

 front ; epistoma much depressed above, conical and lengthened beneath, 

 notched at the tip; peristoma oblong, narrow, straitened in front, 

 but slightly inclined upwards. Eyes pubescent, bare in some species. 

 Labrum long, narrow towards the tip, which is notched. Lingua nar- 

 row, pointed, nearly as long as the labrum. Maxillae subulate, slightly 

 curved, rounded at the tips, longer than the palpi. Palpi cylindrical, 

 short, narrow, pubescent, membranous at the tips, with a few hairs on 

 the side, almost half the length of the labrum. Labium semicylindrical, 

 twice the length of the labrum. Antennae four-jointed, approximate, 

 inserted low in a cavity ; first and second joints small ; first slightly 

 cyathiform; second broader, obliquely truncate, bristly, a little nar- 

 rower towards the tips ; third oblong, compressed, truncate beneath ; 

 fourth and fifth very small ; fourth seated on the base of the third ; sixth 

 setiform, thickly feathered ; its fringe above much broader than that 

 below. Thorax oval. Wings divaricate; subapical areolet entire ; ax- 

 illary lobe distinct ; subcostal and radial veins meeting before tJiey rmch 

 the margin. Alulae with fringed borders. Halteres uncovered. Abdo- 

 men almost oval. Legs rather stout. 



Male. Eyes almost contiguous. Plume of the antennae narrower 

 than that of the female. 



The species may be thus grouped : 



a. Body oblong, almost smooth. Abdomen elongate oval, slightly 

 convex. Larvae parasitic on those of wasps and hornets. Sp. 1. 

 a a. Body short. Abdomen very convex, almost globose. 



b. Body almost smooth. Larvae parasitic on those of wasps. 



Species 2, 3. 

 b b. Body hairy. Larvse parasitic on those of humble-bees. Sp. 4. 



