568 Syrphiiiae. 



in the male there are five not transformed segments on the dorsal 

 side, except the first of nearly equal length ; on the ventral side there 

 are only four not transformed segments, the fifth is not quite sym- 

 metricai, as it is not chitinised quite to the margin on the right side, 

 but has here a broad side membrane, and the apex of the genitalia 

 stretches in below the segment; the other small, transformed segments 

 are distinctly seen below on the left side, and the genitalia are, as 

 usual, turned over to the right; the genitalia are larger or smaller, 

 the hypopygium in some species small, with small, symmetricai claws, 

 in other species (f. inst. cautum) it is large, with very large, curiously 

 shaped, unsymmetrical claws or clasping appendages. In the female 

 the abdomen has five distinctly visible segments, the fifth not small; 

 a small sixth segment is generally also seen, especially below; the rest 

 are hidden, the last terminates with two short lamellæ. The legs are 

 simple, hind femora not thickened, the hind tibiæ have the usual in- 

 curvation on the posterior side before the apex rather pronounced; 

 the legs are haired in the usual way and not strongly; above the 

 trochanters a solitary long hair or a couple of hairs, Claws and pul- 

 villi well developed. Empodium short, spine-shaped, hairy. Wings 

 with the cubital vein curved more or less downwards; medial cross- 

 vein not very oblique, placed before the middle of the discai cell; 

 the basal part of the radial vein with very fine bristles. No stigmati- 

 cal cross-vein. Thoracai squamula with long, richly branched hairs, 

 which have long stems ; besides there are on the marginal part of the 

 surface long, simple hairs; alar squamula with short, flattened hairs. 

 Plumula short, but with relatively long, branched hairs. 



With regard to the developmental stages v. Roser found the larva 

 of C. festivum (arcuatum) in a hollow tree ; he also (according to 

 Schiner) mentions the larva of bicinctum (Wiirttemb. Gorr. Bltt. 1834, 

 267). Beiing (Arch. f. Naturg. XL VIII, 1, 1882, 231) describes the larva 

 and pupa of C. bicinctum ; the larva was found in a compost-heap on 

 ^/4 and developed on ^"/e. Vimmer (Gasopis, Soc. ent. Bohem. VIII, 

 1911) mentions the pupa of C. elegans, but I have not seen this paper. 

 I have myself examined the puparium of C. festivum, to which there 

 were, however, no notes about the way in which it was found. 



According to Beiing the larva of C. bicinctum is flat below, arched 

 above; the segments are divided into corrugations ; on the dorsal side 

 are pointed filaments or spines in transverse rows, those along the 

 sides the largest (these filaments are, no doubt, arranged in the usual 

 way); the posterior end is obliquely declining and has a brown, 

 chitinised posterior spiracular process; the colour of the larva is 

 yellowish white; the length 8 mm. The pupa is of the same length; 



