BY FRANK H. TAYLOR. 751 



markings, and extreme length in proportion to the width of the 

 thorax. 



It affords me great pleasure to associate the name of ray 

 friend, Mr. H. J. Carter, with this striking species. 



SiLVIUS ATER, sp.n. 



9. Length, 13-1-1-; width of head, 4; width of front at vertex, 

 0'5; length of wing, 12-1.3 mm. 



Head: front ashen-grey; frontal callus spear-shaped, dull black, 

 tumid, with a fairly deep, median groove on its apical half, about 

 two-thirds the width of front at its base; ocellar triangle dark 

 brown, prominent, ocelli black; face ashen-grey; antennae pitch 

 black; first two segments clothed with black hairs, base of the 

 third broadly triangular, forming an obtuse angle on its upper 

 edge; palpi black, nearly as long as proboscis, the latter black; 

 eyes black, nude, their inner margins parallel. 



Thurax black, denuded, with traces of black and yellowish 

 liairs on the sides: scutellutn denuded; pleune black. 



Abdomen black, clothed with short, black hairs; first segment 

 broadly marked with grey at the apex and on the sides, second 

 segment with the grey not so prominent on the sides, remaining 

 segments with narrow, more or less distinct, apical bands; venter 

 black, segments two to four with narrow, white, apical bands, 

 five to apex with pale, narrow, apical bands. 



Wings black, a semitransparent streak in the cubital cell along 

 part of the third long vein, the apical, first to fourth posterior, 

 the discal and inferior basal cells with semitransparent spots; no 

 appendix to upper branch of the third long vein. 



Legs black, spurs on mid- and hind-tibiie conspicuous. 



Hah. — Northern Territory: Brock's Creek and Mary River (G. 



r. Hill). 



An easily recognised species, and very different ivom other 

 Australian forms on account of its general black colour, and 

 abdominal markings. 



Co-type in Coll. Hill. 



