AUSTRO-MALAYAN DIPTERA 13 



The macrochaetae on the ahdomen are as follows : on the first 

 segment, a lateral bristle, and a dorsal pair, near the hind 

 margin; second and third segments: a dorsal discal pair and a 

 ditto marginal ; a lateral bristle near the hind margin. 



Tegulae, lower valve much larger than the upper one. 



Legs J, front and hind pair of moderate length (for a Dexia) ; 

 the middle pair twice as long as the front pair (the front legs 

 in my specimen are about 11-12 mm. long; the middle leg 

 25 mm.). The legs, beside the usual, short pubescence, show 

 but a few more conspicuous bristles; there are a few short 

 bristles on the upper side of the front femora; on the underside, 

 there is a row of long , but slender bristles , sparse on the 'pro- 

 ximal portion of the femur, more close together towards the 

 tip ; the front tibiae show a single conspicuous bristle on the 

 hinder side, below; also a pair of apical bristles, besides a 

 number of smaller ones. In the same way, the hind legs have, 

 on the underside, a row of four or more long, slender bristles 

 at ecjual intervals, and a row of shorter bristles on the upper side; 

 the hind tibiae are somewhat incrassated beyond their rather 

 thin base, and bear some scattered bristles. The middle legs 

 •are remarkably bare of bristles. The femora are nearly of the 

 same length as the tibiae in all the pairs. 



Tarsi. Front pair, about 1 Ys ^^^^' length of the tibiae; the 

 relation of the joints is nearly this: 4, 2 Y4? 1 V4' 1' -^• 



Middle pair , a little more than twice the length of the tibiae ; 

 the joints about thus: 2^3? l? ^ Vs' ^ V2' ■^• 



Hind pair about 1 Y3 the length of the tibiae ; the relation 

 of the joints is nearly the same as in the front pair: 4, 2 Ys^ 

 2,1,^/4. 



Ungues of moderate size, slender; pulvilli large. 



Wings rather narrow; venation of the Dexiariae; no costal 

 spine; first posterior cell narrowly open; elbow of fourth vein 



