228 DIPTERA OF AUSTRALIA, 



beyond it. First longitudinal vein reaching costa beyond middle. 

 Second and third longitudinal veins originating together from 

 first longitudinal vein at apex of middle cross-vein, which may be 

 situated before, at or beyond middle of wing ; second longitudinal 

 vein usually very pale and indistinct, or wanting (?). Third 

 longitudinal never furcate, bent upwards or downwards towards 

 tip. Fourth longitudinal never furcate, originating at base of 

 fifth longitudinal, usually slightly angulated at middle cross- 

 vein, gently arcuated anteriorly, straight, or somewhat sinuose 

 beyond it, not quite reaching wing-margin, or indistinctly reaching 

 it, at or below the apex.* Fifth longitudinal vein forked before, 

 at or beyond middle of wing, fork acuminate at base ; anterior 

 branch straight or slightly arcuated posteriorly, longer than 

 posterior, latter straight, slightly arcuated or sinuose. 



Genus 1. Chironomus, Meig. 



Chironomus, Meigen, Illiger's Mag. II. p. 260, 1803; Latreille, 

 Gen. Cr. et Ins. lY. p. 248; Macquarfc, S. a B. I. p. 47, 1834; 

 Zetterstedt, D. Sc. IX. 1850; Walker, LB. p. 149, 1856; Schiner, 

 F.A. Dipt. 1864; V. d. Wulp, Tijd. Entom. XVII. p. 129, 



1873-74. 



Antennae 2--f 12-jointed in (J, 2- -i- 5-jointed in 9. Thorax 

 usually with three stripes. Wings naked. Costal vein not 

 extending beyond tip of third longitudinal vein. In fore legs 

 metatarsus longer than tibia, or (by exception) at least as long 

 as it. Anal joint of J abdomen longer than broad; forceps 

 generally filiform or falcate. 



* In most cases it is impossible, without the aid of the microscope, to 

 discover that the fourth longitudinal vein does not really reach the wing- 

 margin ; the ordinary entomological lens will rarely reveal the fact. 



