204 



Transactions. 



Fig. 11.— Profile of head. 



of a very dark madder-brown ; a pair of strong proclinate ocellar bristles 

 and a similar but larger pair of post-ocellars ; frons narrow, wedge-shaped 

 and small, witli dense brownish tomentum. Antennae dull black, micro- 

 scopically pubescent, tlie distal portion of the 

 flagellum and the terminal appendix dark brown ; 

 1st joint short and bristly; 2nd joint globular and 

 bristly, the outer ones longer ; 3rd joint about 

 twice as long as the 1st and 2nd together, the 

 terminal flagellum almost as long as the 3rd. 

 Face not seen in profile, black with a greyish- 

 brown tomentum ; the lower margin of the head 

 with grey hairs ; proboscis and palpi withdrawn, 

 but in profile is a hairy shiny-black knob-hke 

 protuberance somewhat resembhng a palpus 

 (fig. 11) ; occiput black with a greyish-brown tomentum and stiff hairs, the 

 lower corner being considerably produced. 



Thorax short, prominently humped (fig. 12). the dorsum brownish-black, 

 but fighter just before the scutellum, and with 

 a lateral fight-brown stripe from the post-alar 

 callus to the humeri, widening anteriorly ; 

 the chaetotaxy is represented by a few stift' 

 humeral hairs, 2 rows of short light-coloured 

 hairs, lengthening posteriorly, each ending in 2 

 stronger bristle-like post-suturals just iaefore 

 the scutellum ; the post-alars weak, but those 

 opposite the base of the wing more distinct, as 

 well as the marginal ones of the scutellum. 

 Pleurae greyish-brown, due to a tomentum, 

 bare but for 3 bristle-fike curved hairs above 

 the anterior coxae (fig. 12). Scutellum light 

 brown on the margin, but darker towards the 

 base. 



Wings brown, the stigma very dark, a clearer space between the end of 

 the 2nd and the anterior branch of the 3rd vein, in the 2nd, 3rd, and 4th 

 posterior cells, in the discal cell, and less distinct ones in the other cells ; 

 the veins dark brown, but fighter distally ; the auxihary vein, which on 

 account of the folding of the wing appears approximated to the 1st vein, 

 ends in the costa ; 2nd vein strongly upturned at the tip ; 3rd vein forked, 

 the strongly sinuated anterior branch arises at an acute angle, and, curving 

 forward for about half its length, bends backward to the costa, the posterior 

 branch being straight ; a fittle before the middle distance between the in- 

 sertion of the anterior transverse vein and the bifurcation of the 3rd longi- 

 tudinal is a supernumerary cross-vein at right angles connecting the 2nd 

 and 3rd veins ; this singular cross-vein is constant in both wings of all the 

 specimens of this species in my possession ;* the anterior branch of the 



Fig. 12. — Side view of thorax. 



* I have observed supernumerary cross-veins in other species of Diptera, but, ag 

 a rule, they are not constant in both wings, and, as in the case of Calliphora hortona., 

 are absorbed as the fly matures after pupation. Is it therefore possible that the cubital 

 appendices, which in some cases form specific characteristics, are not trustworthy 

 features ? Space permitting, I could enumerate a few cases of New Zealand Tachi- 

 nidae, for example, where the cubital appendix of the 4th vein is sometimes present 

 or longer in one wing and absent or shorter in the other. In B. adelensis, the anterior 

 branch of the 3rd vein and that of the 4th vary in the strength of the sinuation. 

 Plate 1, fig. 2, is a moderate form? 



