Dolichopodidae. 391 



only the apices free; these latter are generally seen, when the hypo- 

 pygium is in situ, and often also the lobes ; more basally on the 

 ventral side there are a pair of flat pieces each with some teeth. 

 Penis short. In the female the abdomen is truncate; it has seven 

 visible segments, and at the end generally also the somewhat smaller, 

 eighth segment is seen. Dot-like impressions are, I think, present on 

 some of the segments, but rather indistinct. The abdominal segments 

 have distinct hindmarginal bristles, long on the lirst segment. Legs 

 slender and rather long, hind tarsi somewhat short, shorter than the 

 tibiæ, with the first joint somewhat longer than the second, without 

 bristles ^ Posterior coxæ each with a bristle; femora without preapical 

 bristles; middle tibiæ with two antero-dorsal and one postero-dorsal 

 bristle; posterior tibiæ with apical or preapical bristles. There are 

 two small claws, two small and short pulvilli, and a narrowly lobe- 

 shaped empodium with bristles below. Wings of usual shape; the 

 mediastinal vein terminating in the subcostal vein; discai vein slightly 

 curved, a little converging towards the cubital vein; posterior cross- 

 vein about in, or a little before the middle; anal vein short. Axillary 

 lobe moderately developed. There is a distinct convexity in the 

 middle of the last part of the discai vein. Squamulæ with a distinct 

 angulary lobe, bearing a long fringe ; the inner part of squamulæ with 

 short hairs. 



The developmental stages are not known. 



The species of XanthocJilorus are rather characterlstic by their 

 prevailing yellow colour, and the abdomen which is knobbed at the 

 end in the male and rather truncate in the female. They occur in 

 bushes and low herbage in more or less shady piaces, thus often in 

 low herbage on humid ground in woods, but also outside woods at 

 ditches and the like. 



Of the genus 2 palæarctic species are known, both occurring in 

 Denmark. 



Tahle of Species. 



1. Thorax and "scutellum green or æneous, grey pruinose l.ornatus. 



— Thorax yellow, with a green or æneous patch, scutellum yellow 2. tenellus. 



1. X. ornatus Hal. 



1831. Hal. Zool. Journ. V, 358, 17 {Medeterm). — 1862. Schin. F. A. I, 

 184. — 1903. Kat. palåarkt. Dipt. II, 350. — Dolichopus tenellus Fall. (nec 



^ Loew says both in Neue Beitr. V, 4^, and in Mon. of Dipt. of N. Am. II, 2'23, in 

 the description of the genus, that the hind metatarsus is shorter than the 

 second joint, while it is in reahty somewhat longer in both European species, 

 and in Loew's figure of X. helvinus in the latter work PI. VII, fig. 41 it is also 

 longer. 



