804 DIPTERA OF AUSTRALIA, 



The tibiae of the males in some, if not the majority, of species 

 exhibit a sexual character which does not appear to have been 

 noted, or recorded, by previous authors. This is an annular 

 swelling or nodosity, hardly perceptible in some instances but often 

 prominent and dark-coloured, situated close to the base of the fore 

 tibiae. It would seem that North American species do not have 

 this, since Baron Osten-Sacken does not allude to it in his mono- 

 graph and being present it could scarcely have escaped his notice. 



323. MoLOPHiLUS RUFicoLLis, sp.n. 



^. — Length of antennas '070"^ inch ... 1.77 millimetres. 



Expanse of wings 0-220 x 0-065 ... 5-58x1-66 



Size of body 0-170x0-035 ... 4-31x0-88 



(^. — Length of antennae .... 0-070 inch ... 1*77 millimetres. 



Expanse of wings 0-220x0-065 ... 5-58x1-66 



Size of body 0-180x0-035 ... 4-56x0-88 



Head, including rostrum, palpi, and antennae dark brown ; 

 flagellar joints sub-cylindrical, somewhat fusiform, densely and 

 uniformly verticillate- pilose ; collare with long golden hairs. 

 Thorax reddish-brown, levigate, with two longitudinal rows of 

 brown hairs ; humeri with an ochreous spot ; a patch of long 

 yellow hairs behind the origin of wings. Hal teres light fulvous- 

 brown with golden pubescence. Abdomen dusky brown, clothed 

 with golden-yellow pubescence ; male forceps reddish-brown ; 

 ovipositor short, curved, ochreous, or brownish-ochreous. Coxae 

 reddish-brown. Remaining joints dusky brown ; the femora with 

 a yellow ring a little before their tip (broader on the hind pair) ; 

 . hind femora stout. Wings sub-hyaline (when denuded) ; some- 

 what clouded in the vicinity of bases of sub-marginal cells ; the 

 veins brownish, with dense long hairs, covering the cells ; the 



* The stated length of the antennae in this and some of the following small 

 insects is only approximate, owing to their being sometimes very difl&cult 

 to measure. 



