282 DIPTERA OF AUSTRALIA, 



pallid. Abdomen nearly three times the length of thorax, very- 

 pale ochreous-yellow, each segment with a broad ill-defined band of 

 brown, clothed with yellow hairs ; anal joint very pale ochreous- 

 yellow, forceps brown. Legs very pale ochreous-yellow, densely 

 covered with pale hairs. In fore legs tibia a little longer than 

 metatarsus. Wings about the length of abdomen^ pellucid, almost 

 hyaline, densely haired, veins pale ochreous-yellow. Costal meeting 

 third longitudinal vein much before apex of wing ; latter vein 

 running parallel with first longitudinal ; auxiliary vein terminating 

 about mid- way between origin of third and tip of first longitudinal 

 vein; second longitudinal and marginal cross- vein extremely indis- 

 tinct,* close to first longitudinal ; middle and posterior cross-veins 

 equal in length, latter situated somewhat before former ; fourth 

 and fifth longitudinal veins pale and indistinct past cross-veins. 



Rab. — Wheeny Creek, Hawkesbury District, N.S.W. (Skuse). 

 January. 



Obs. — I have seen only a single specimen. 



269. ISOPLASTUS FORMULOSUS, sp.n. (PI. XII., fig. 26). 



(J. — Length of antennae 0*040 inch 



Expanse of wings... 0-080 x 0-020 .. 



Size of body 0-100x0-017 .. 



9- — Length of antennse 0-030 inch 



Expanse of wings 0-080x0-025 .. 



Size of body 0-060x0-017 .. 



1-01 millimetres. 



2-02x0-50 



2-54x0-42 



0-76 millimetre. 



2-02x0-62 



1-54x0-42 



(J and 9- — Antennae pale ochre-yellow, with pale yellow verti- 

 cils. Head, clypeus and palpi brown or ochreous-brown, with 

 yellow hairs. Thorax ochreous or light umber-brown, dull, tra- 

 versed for its whole length by three longitudinal, parallel rows of 

 rather long yellow hairs ; pleurae and pectus brown ; scutellum 

 ochreous or ochreous-brown, fringed with pale yellow hairs ; 



* In this and the following species these two veins are so indistinct that 

 they might be regarded as absent, and what are taken to be indications of 

 them may result from wing-folds or even from the pubescence of the wing. 



