486 Syrphidae. 



Genitalia relatively large. The lamellæ at the end of the female ab- 

 domen somewhat long. Legs with the femora somewhat thickened, 

 tibiæ a little curved, especially the hind tibiæ and these latter a little 

 thickened about the middle and with the usual shght incurvation 

 before the apex on the posterior side; the legs rather short-haired ; 

 the femora sulcate and spinose below the apical part ; the curious small 

 bristle above the trochanters present, Glaws and pulvilli well developed; 

 empodium short, bristle-shaped. Wings with the cubital vein im- 

 perceptibly curved down above the first posterior cell; medial cross- 

 vein before the middle of the discai cell and slightly oblique; anal 

 vein nearly straight; there are distinct, fine bristles on the basal part 

 of the subcostal vein, continuing out on the radial vein to near the 

 base of the cubital vein; no stigmatical cross-vein. Thoracai squamula 

 with long, fine, branched hairs, alar squamula with short, slightly 

 flattened hairs. Plumula somewhat short, with simple hairs. 



The developmental stages are somewhat well known. Becher 

 describes (Wien. ent. Zeitg. I, 1882, 250) larva and pupa of M. obscura 

 and the pupa of M. luteola. The larva of obscura was found in a 

 hollow poplar in the middle of March, it pupated on ^^/a and the 

 imago came on ^^/4; the pupa of luteola was found on the same place 

 at the end of May and first in June, and the imago came at the 

 middle of June. I have myself examined the pupa of M. luteola. 

 found in the decaying wood in a hollow beech on Vt, the imagines 

 came on ^/t and ^^h. According to Brauer the larva of M. luteola has 

 also been found in decaying wood of a maple-tree. The larva of 

 M. obscura is, according to Becher, whitish, somewhat cylindrical but 

 with the ventral side flattened; it is tapering behind and has here a 

 thin, chitinised spiracular tube, telescopically pro- and retractile, and 

 with hairs stellately arranged at the end; above the mouth are the 

 two-jointed antenna-like papillæ sitting on a basal piece; there are no 

 mouth hooks; on prothorax are short anterior spiracular tubes. The 

 prothoracal segment is longitudinally wrinkled, the body otherwise 

 with transverse corrugations ; on the ventral side are six pairs of 

 spined prolegs. At the sides of the posterior segments are some 

 filaments with hairs at the end, the last pair the longest. The length 

 in all (of a probably not quite fuU-grown larva) is 13 mm, the tapering 

 part and the tube of which measure 4 mm. The pupa of M. luteola 

 is quite agreeing with the above description of the larva; it is curious 

 that Becher sta'tes for the pupa of both obscura and luteola that they 

 are "von einem (weisslichen respective gelblichen) reifartigen Ueber- 

 zuge dicht bedeckt"; this is evidently caused only by the clay-like 

 substance in which they live; Becher says that for this reason he 



