AUSTRO-MALAYAN DIPTERA 11 



I. Urodexia nov. gen. 



(Dexinae) 



Belongs to the Dexinae with a glabrous arista, and will be 

 easily recognized by the shape of the abdomen, which ends in 

 a long, subcylindrical , slender, slightly tapering tail, beset 

 with scattered bristles and ending in a blunt point; the middle 

 legs are enormously prolonged. 



Head a tritìo broader than the thorax, projecting very httle 

 in front of the eyes, and very flat behind them; so that the 

 vertical margin is very abrupt, the occipital orbit of the eye 

 reduced to nothing above, and gradually increasing downwards; 

 lower occipital orbit moderately swollen ; cheeks narrow. 



Eyes large , their horizontal diameter equal to about one half 

 the vertical; they descend very low (the cheeks being narrow) 

 and are glabrous. 



Facial orbits narrow, glabrous; narrowest below, where the 

 frontal fissure almost comes in contact with the eye; broader 

 near the antennae; the face, between the orbits, shows two 

 furrows of moderate depth running from the base of the an- 

 tenna to the peristomium ; the interval between them is nearly 

 level (therefore no intrafoveal ridge to speak of); these furrows 

 are not the antennal foveae , the latter being almost obsolete ; 

 in a favorable light two impressions, representing them, are 

 visible. A single vibrissa , of moderate strength , is inserted near 

 the end of the above-mentioned furrows , a little above the pe- 

 ristomium; a few (3-4) smaller bristles below the vibrissa, a 

 single small bristle still lower , on the cheek , near the lateral 

 peristomium; a few minute hairs above the vibrissa on the edge 

 of the lower falciai orbit.. Peristomium nearly horizontal, almost 

 imperceptibly arched between the vibrissae ; its edge glabrous. 



Frontal orbits moderately broads coalescent on the vertex, 

 separated lower down by a long and narrow triangular frontal 

 stripe ; they are beset with bristles, from the antennae upwards, 

 as follows: 6 or 7 bristles in a row, beginning near the an- 



