[Proc. Roy. Soc. Victoria, 33 (N.S.), 1021]. 



Art. II. — Description of a New Species of Corethra 

 (MocJdonyx) from Australia. 



By E. W. FERGUSON, M.B., Ch.M. 

 [•Read llth March, 1920.] 



The sub-family Chaoborinae (Corethrinae) is poorly repre- 

 sented in Australia, the only species previously recorded being 

 Chaoborus (Corethra) qaeenslandensis, Theob. The discovery 

 •of a species belonging to the genus Corethra is therefore of special 

 interest, particularly as the genus has hitherto been recorded only 

 from the Northern Hemisphere. I have followed Brunetti (Re- 

 cords Indian Museum, IV., 1911, p. 317) in sinking Mochlonyx, 

 Loew, 1844, in favour of Corethra, Meigen, 1803. 



Corethra australiensis,, sp. n. 



Small, dark brown, legs yellowish, unbanded. 



c? Head dark brown, clothed with greyish tomentum, brown- 

 ish near base, with long somewhat scattered brown hairs ; palpi 

 brown with brownish hairs, longer on basal joints; antennae 

 plumose, brown, the basal part of each joint behind the whorl 

 .and the extreme apex white, the two apical joints entirely brown; 

 hairs long, brown, set in whorls on each joint, except the last 

 two, on which the hairs are shorter, and which are also clothed 

 with fine whitish pubescence. Thorax dark brown, with a nar- 

 row median darker line; densely clothed with yellowish brown 

 tomentum, more greyish posteriorly, and with scattered brown 

 hairs. Abdomen dark brown, somewhat lighter at bases of seg- 

 ments, with scattered brown hairs, a few yellowish ones inter- 

 mingled ; apical segment with lobes short, stout, rather strongly 

 curved; venter with scattered yellow hairs. Wings hyaline, veins 

 light brown rather thinly set with dark brown setose hairs, first 

 fork cell one and a-half times the length of second, its base nearer 

 to base of wing, the first cell two and a-half times as long as stem ; 

 posterior cross vein short, about twice its length distant from 

 mid-cross vein. Legs yellowish, with brown hairs, tarsi broken. 



? Agrees with male, with the usual sexual differences: An- 

 tennae with shorter whorls and lighter brown ; palpi darker than 

 rantennae; head with rather conspicuous golden yellow hairs. 



