Ghrysosoma. 4il5 



bristles quite small. Postocular bristles long and fine, with no black 

 hairs behind. Frontal bristles descending just below insertion of 

 antennæ, all crossing in male. Cheeks bare. Vibrissæ not ascending. 

 Eyes hairy. Epistoma retreating, hollowed in the middle, reflected 

 and prominent below. Oral bristles well developed. Oral cone and 

 proboscis about equally long; labella relatively not small; palpi 

 tbread-like, in female a little dilated outwards. Antennæ inserted 

 at about middle of the eye, not reaching the end of epistoma, third 

 joint about double second, dilated in male, less in female; arista 

 with second joint a little elongated, visibly pubescent. Thorax rect- 

 angular; three postsutural dorsocentrals, and three præ- and three 

 postsutural acrostichals; a præsutural intraalar bristle. Scutellum 

 with five marginal bristles on each side, the apical small, crossing. 

 Three sternopleural bristles. Above on pteropleura a couple of 

 bristles^. Abdomen ovate; excavation on second segment reaching 

 hind margin; sternites concealed; there are discai and marginal 

 bristles, second segment without bristles, fifth with bristles about all 

 over. Fifth sternite cleft to base, the lamellæ excised in the hinder 

 angle. Genital knob not much protruding; upper forceps short; arms 

 of lower forceps broad at base, ending in an obtuse apex, longer than 

 upper. Legs with claws and pulvilli elongated in male ; front tarsi in 

 female simple. Wings with first posterior cell open, ending a little 

 before apex of wing; discai angle rectangular, without veinlet; 

 cubital vein with bristles to near medial cross- vein; no costal spine. 



The species is parasitic on Heterocera and belong to Pantel's 

 group 4. 



Of the genus two species are recorded, but only auratum is well 

 known, also occurring in Denmark. 



1. C. auratum Fall. 



1820. Fall. Dipt. Suec. Muse. 25, 52 (Tachina). — 1824. Meig. Syst. Beschr. 

 IV, 257, 31 {TacUna) et 1838. VII, 217, 1. — 1844. Zett. Dipt. Scand. III, 

 1191, 194 {Tachina). — 1862. Schin. F. A. I, 431 {Gymnochaeta). — 1889. B. B. 

 Denkschr. Akad. Wiss. Wien, LVI, 134, Tab. X, Fig. 251. — 1896. Pand. 

 Rev. Entom. XV, 2, 1 [Exorista). — 1907. Kat. palåarkt. Dipt. III, 209. — 

 1921. Baer, Zeitschr. f. angew. Ent. VII, 132. — 1924. Stein, Arch. f. Natur- 

 gesch. 90, 6, 164 [Chrysocosmius). 



^ In a key (Insec. Insc. Menstr. XIV, 1926, 62) Aldrich says about the genus 

 {=^ Chrysosomopsis Towns.) that the pteropleural is larger than sternopleurals ; 

 this is not the case in my specimen. 



