148 Miss G. E-icardo — A Revision of 



Atomosia^ Macquart. 

 Dipt. Exot. i. p. 73 (1838). 



Formed for species from America. No Australian species 

 has been described as belonging to this genus so far, though 

 one from New Guinea described by Walker under Laphria 

 is placed bere by v. d. Wulp ; but a new species from 

 Victoria appears to belong to this genus. T compared it 

 with the type of Atomosia affinis, Macq., from Brazil, in the 

 Paris Museum, and it appeared to agree with it in generic 

 characters. 



The genus belongs to the group with no curved spine on 

 fore tibiae, and has the cross-veins closing the discal and 

 fourth posterior cells parallel. 



Atomosia australis, ^ ? , sp, n. 



Types from Dandenong Ranges, Victoria, 



A small blue-black species, with white-haired tibiae. 

 Wings shaded on the cross-veins. 



Length 9 mm. ( c? ), 8 mm. ( ? ). 



Face with grey tomentum, brown in centre below the 

 antennse ; no tubercle present ; moustache consists of rather 

 long, weak, black hairs, reaching entirely over face as far as 

 the antennce ; one or two white hairs near the mouth ( ? ) ; 

 in the c? the face is more widely brown and the moustache 

 consists of long yellow hairs below and black above. An- 

 tenna> black, the first joint quite twice as long as the second, 

 which is small, the third about one and a half times as long 

 as the first two, with no end-bristle, the first two joints with 

 black pubescence; back of head with long black hairs, beard 

 and pubescence on lower part of head white. Thorax 

 brownish, with short fulvous pubescence ; scutellnm similar, 

 with long weak bristles posteriorly. Abdomen blue-black, 

 shining, the same width throughout, finely punctuate ; sides 

 and apex with fine white pubescence; underside brown; 

 some black bristles at apex of abdomen. The male has the 

 abdomen somewhat darker, the genital organs distinctly 

 visible on the underside. Legs black, coxse reddish brown, 

 the femora with white hairs below, the tibise covered with 

 white pubescence on the upper side and with black bristles on 

 each border, the tarsi with black bristles and pubescence. 

 Wings clouded with brown on the cross-veins ; the anterior 

 branch of third vein curved ; the subcostal cell closed in a 

 point, the first posterior and discal cell narrow, the second 

 and third wide, the fourth closed, the cross-vein closing it is 



