of some new Species of Mydasida. 89 



segment is armed with two horny lobes (fig. 2 b **), and with 

 two curved hairy fihiments (2b -j-f). The legs are pale yellow, 

 with the middle of all the femora and the apical half of the 

 posterior tibiae black. The hind femora are clavate and serrated 

 beneath. The wings are very slightly tinged with brown, having 

 the costa and the space along the two chief veins rather more 

 clouded with brown. The fourth longitudinal vein, which is fur- 

 cate towards the extremity of the wing, is suddenly deflexed at a 

 little distance in front of the furcation, crossing the next vein at 

 right angles, being connected with the anterior branch of the basal 

 cell (which branch, in the majority of the species of the genus, 

 extends beyond the spot where the fourth longitudinal vein is con- 

 nected with the fifth). The halteres are white. 



The female of this species differs from the male in having the 

 abdomen long and narrovv, but not narrowed at the base, being 

 of nearly equal width throughout; and the joints being rather 

 widened beyond the middle. The terminal segment is black, the 

 second and third with a large fulvous yellow spot on each side, 

 and the three succeeding segments with a broad fulvous yellow 

 fascia. 



The last segment is terminated by a rounded appendage, each 

 side of which is armed with six short blunt spines. (Fig. 2c, 2c?.) 

 The wings (or rather wing, as the only specimen of this sex which 

 I have seen possesses only one wing) differs from the male in 

 having the cell formed by the fourth longitudinal vein of the wing 

 closed and appendiculated at the tip. (Fig. 2e.) 



Fig. 2. The male insect magnified; 2a, the head seen sideways; 2b, the 

 extremity of the male abdomen from beneath ; 2c, the extremity of 

 the female abdomen, seea from above ; 2 d, the same, seen from 

 beneath ; 2e, portion of the veins of the wing of the female. 



Mydas sordidus, Westw. (Plate XIII. fig. 3.) 



Mydas opacus, niger ; antennis brevioribus, apicibus rufis ; seg- 

 mentis abdominis basi utrinque macula parva triangulari 

 lutea ; pedibus piceo-rufis ; femoribus posticis obscuris ; alis 

 limpidis, venis nigris. 5 



Expansio alarum fere l^ unc. 



Habitat prope Adelaidam, Australise occidentalis. D. Fortnum. 



In Mus. Hope. 



The head is black, with the nasus obscure fulvous, rounded, 

 rather prominent and obliquely truncate above the mouth ; the 

 face is clothed with grey hairs. The antennae are shorter than in 



