;270 Syrphidae. 



been found between ^'Vt and ^'Vs on Rosa, Rheiim, Typha and Phrag- 

 mites, one found ^^Is developed '/,s, another found ^/s developed "^/s, 

 and a third found ^'^/s developed ^^/s; finally a pupa of S. cinctellus 

 was found on the stem of a tree on ^*/7 and developed some 

 days latei*. 



The larva is always more or less leech-like: it is somewat flat- 

 tened, with a flat ventral surface, the dorsal surface more or less. 

 generally slightly arched; the body is attenuated or pointed towards 

 the head-end, broad behind, sometimes a little rounded; it is more 

 or less strongly transversely corrugated so that the single segments 

 are not easily made out. Below there are seven more or less distinct, 

 transverse swellings, which may be more or less distinctly divided 

 into proleg-like warts, and have small spines. The larvæ may other- 

 wise be somewhat different; some are almost smooth above, the 

 dermis only finely chagreened, and there are short, soft bristles on 

 some of the corrugations and at the sides; in others the chagreened 

 strueture is developed into a clothing of fme, short and dense spines, 

 and there are the same soft bristles; in a third group the dermis is 

 rather coarsely chagreened, and on the dorsum of the segments are 

 large, conical warts, and similar at the sides or here they are developed 

 into conical filaments; the short bristles and the conical warts or 

 filaments, which answer to each other, are present in the same number 

 and arranged quite in the same way as described above for Platy- 

 chirus and Lasiophthicus; there are consequently on the meso- and 

 metathoracal segments six in a transverse row, besides a couple at 

 the side ; on the first abdominal segment there are likewise six, placed 

 on one corrugation, and on the next six segments two in the middle 

 on one corrugation and two at each side on the next corrugation, 

 and on all seven abdominal segments three on each side; each seg- 

 ment shows four corrugations divided by furrows, and the bristles or 

 warts are placed on the two middle corrugations of each segment. 

 The anterior spiracles are small, lying on each side of the prothoracal 

 segment ; the posterior spiracles are placed above on the last segment 

 on a short, slightly longitudinally divided process, more or less ellip- 

 tical in a transverse section. The mouth is provided with hooks, and 

 the head is much retractile and able to be stretched out, and the 

 whole body is likewise very contractile, so that the larva may alter 

 its shape to a i-ather high degree; when fully stretched out it is long, 

 broad and flat, when contracted it is much shorter, higher and nar- 

 rower. The colours may be various, yellowish, yellowish grey, grey. 

 reddish grey or darker, generally more or less marmorate from darker 

 designs and often with one or more longitudinal lines. The pupa 



