38 DIPTEEA. 



AOCHLETUS, gen. nov. 

 Resembles Oocycera in its general appearance and colouring ; the principal difference 

 consisting in the structure of the antennae, in which the terminal aristiform style is 

 replaced by a stout, elongate joint. 



Antennae, in both sexes, not longer than the longitudinal diameter of the head; 

 first joint slender, sub cylindrical, the second not much shorter, but stouter, both 

 beset with short hairs ; the first three joints of the flagellum are broader than long, and, 

 taken together, form a cylindrical body about as long as the antennal scapus, but 

 stouter ; the fourth joint of the flagellum is not unlike the preceding in shape, but a little 

 narrower, and separated from it by a distinct coarctation ; upon this follows an elongated 

 body, a little longer than the two preceding joints taken together, without any distinct 

 articulations, and placed somewhat at an angle to the axis of the antenna; in the male 

 this last joint is more flattened than in the female.— N.B. I have only two specimens 

 tor comparison ; to give an accurate description of the antenna?, fresh or living specimens 

 would be necessary. 



The occipital orbits of the female are like those of Oxycera. 

 Thorax and scutellum as in Oxycera. 



The abdomen of the male is narrower than in the Oxycera known to me, elongated, 

 about three times longer than broad, almost a half-cylinder in shape, slightly coarctate 

 near the base ; that of the female is broader and flatter, more rounded. 



The antennas are inserted in the middle of the profile ; the face flat, oblique ; the 

 eyes glabrous in the male, subcontiguous for a length a little less than that of the 

 face, the upper facets separated by a distinct line from the lower ones, which are of a 

 different colour; front of the female broad. 



Venation like that of Oxycera, but there is no branch to the third vein ; of the four 

 veins issuing from the discal cell, the anterior one is very weak. 



These last characters may be as variable in Aochletus as they are in Oxycera or in 

 Euparyphus ^Schiner, Fauna Austr. i. p. 9, is not right in describing the third vein of 

 Oxycera as being always branched) ; the structure of the front and face may also vary; 

 the eyes, in some as yet undiscovered species, may be pubescent, as they often are in. 

 Oxycera. The chief generic character is in the structure of the antennas. 

 In short, Aochletus is an Oxycera with a stout terminal joint to the antennas, instead 



of an aristiform style. 



It differs from Euryneura, Schin., in the position of the antennas, which in the latter 



are close above the oral edge. 



Aochletus, in Greek, means undisturbed, unruffled. 



l. Aochletus cinctus, sp. n., s $ • 



Male Face and frontal triangle yellow ; facial orbits broad, silvery (or black, when the light is not reflected 

 fromtbexn); vertical triangle black; antennas brownish-yellow at the base, browner towards the txp. 



