Gymnochaeta. 409 



about equal length; clypeus not long, horse-shoe-shaped; labium 

 rather short, labella roundish, relatively large; labriim almost as 

 long as labium, hypopharynx shorter, thin; palpi a little dilated. 

 Antennæ inserted just below middle of the eye, third joint not much 

 longer than second; arista with second joint a little elongated. Thorax 

 rectangular; four postsutural dorsocentrals and three præ- and three 

 postsutural acrostichals (generally); no præsutural intraalar bristle. 

 Scutellum with four marginal bristles on each side, the apical as 

 strong as the others, diverging; a pair of discai bristles. Three sterno- 

 pleural bristles. Pteropleura with a couple of bristles above. Abdomen 

 with excavation on second segment reaching hind margin; the sternites 

 not concealed ; there are discai and marginal bristles, second segment 

 without bristles. Fifth sternite large, reaching the end of abdomen, 

 cleft to near base. Hypopygium small; upper forceps triangular, 

 pointed, s-like curved with the apex inwards; arms of lower forceps 

 rod-like, a little curved and slightly dilated at end, together forming 

 a forceps as long as upper. Legs with clawg and pulvilli elongated 

 in male; front tarsi in female with the three last joints slightly 

 dilated. Wings with first posterior cell narrowly open, ending somewhat 

 before apex of wing; discai angle rectangular, with a veinlet; a small, 

 sometimes indistinct costal spine. 



The species has been bred from Heterocera and belongs to Pan- 

 tel's group 4 (Thompson 1923). 



Only one European species belongs to the genus, also occurring 

 in Denmark. 



1. G. viridis Fall. 



1810. Fall. Vet. Acad. Handl. XXXI, 253 et 1820. Dipt. Suec. Muse. 

 25, 51 (Tachina). — 1824. Meig. Syst. Beschr. IV, 258, 32 (Tachina) et 1838. 

 VII, 217, 2, Tab. LXX, Fig. 6—11 [Chrysosoma). — 1844. Zett. Dipt. Scand. 

 III, 1190, 193 et 1859. XIII, 6143, 193 {Tachina). — 1862. Schin. F. A. I, 431. 

 — 1889. B. B. Denkschr. Akad. Wiss. Wien, LVI, 87, Tab. I, Fig. 7 et 1891. 

 LVIII, 318. — 1896. Pand. Rev. Entom. XV, 32 {Exorista). — 1907. Kat. 

 palåarkt. Dipt. III, 210. — 1921. Baer, Zeitschr. f. angew. Ent. VII, 131. — 

 1924. Stein, Arcli. f. Naturgesch. 90, 6, 67. 



Male. Metallic green species. Frons above about half as broad 

 as the eye, rapidly widening downwards. Orbits a little greenish, 

 silvery along the eye-margin or almost quite silvery; cheeks and 

 epistoma silvery seen from above, from in front more or less dark; 

 jowls metallic green, greyish pruinose; frontal stripe blackish or 

 slightly brown. Orbits with a few, fme black hairs; jowls with black. 



