Tachinidae. 57 



I. Gastrophilinae. 



Tilis subfamily is rather aberrant. No hypopleural bristles. The 

 discai vein runs straight to the margin, and costa reaches only to 

 the end of cubital vein or a little beyond. Ventral membrane present. 

 No sternopleural bristles. Squamulæ small. Middle part of epistoma 

 between the ridges narrow and linear. Densely pilose species without 

 bristles. 



The species are parasitic on horse. 



Only one genus 1 . Gastrophilus. 



II. Oestrinae. 



Ventral membrane present. Hypopleura with a fan of strong 

 pale hairs. No sternopleural bristles. Middle part of epistoma narrow. 

 Not pilose species; no bristles present. 



The species are parasitic on mammals. 



Only one Danish genus 2. Oestrus. 



III. Hypoderminae. 



Ventral membrane present. Hypopleura with a bundle of pale 

 hairs. No sternopleural bristles. Middle part of epistoma broad, 

 square. Densely pilose species without bristles. 



The species are parasitic on ruminants. 



Only one Danish genus 3. Hypoderma. 



IV. Phasiinae. 



The species of this subfamily are of rather varied aspect; they 

 may be rather broad and flat, or globose, or of more common shape, 

 or on the contrary very elongated. Sometimes the wings are specially 

 broad. Generally they are characterised by having only relatively 

 few and weak bristles both on head, body and legs. Frons either 

 more or less narrow in male, broader in female, or nearly equal in 

 both sexes; in Allophora and Xysta narrow and most narrow in 

 female. As a rule the frontal bristles are all crossing, and they stop 

 generally at the insertion of antennæ, and as a rule no orbital bristles 

 are present; rarely an upper outwards directed bristle in female. 



