A DESCRIPTION OF HETEROMETOPTA AJiOEXTEA 

 MACQUAliT (DIPTEEA DEXIID.E). 



BY 



G. H. Haruy. 



(Plaie xxxvii ) 



This paper is the first of a series in whicli it is proposed to desciube, 

 more thoroughly than has hitherto been done, those Australian species of 

 the Calyptrata which aie the typical forms of various genera proposed by 

 the earlier authors such as Macquart and Walker. 



Considerable difficulty has been experienced in determining the genera 

 and species that were described bj' most of these earlier authors, partly 

 owing to the inadequate descriptions, and partly to the lack of the 

 complete literature dealing with the subject; nevertheless a certain 

 amount of recent and useful information has been aiid is still being 

 published upon this group of Diptera, and this, together with the 

 literature available at the present time, has made it possible for me to 

 ascertain the identity of various species. 



The Dexid described here was oiiginally placed under the Tachinidse, 

 and besides being typical of its genus it is the origin of a curious 

 phenomenon which forms a subject matter under the notes. Moreover the 

 sexes are determined, and the female is now described for the first time, 

 unless perchance it has been described previously under another name. 



Heterometopia arokntea Macqtiarf. 



(Plate xxxvii.) 



Heferoiiietdplu uryeiifpu Macquarf, Dipt. Exot. suppl. 1, IS^G, p. 170; PI. 

 xvi., fig. 1. 



Colours. — Seen from the front the whole dorsal surface of the male 

 appears to be silvery ; this is due to a tomentuni which is seen at its best 

 in this position. As tlie insect is turned to some other position the ground 

 colours become apparent, and are seen at their best when viewed from 

 the rear. There is less silvery tomentuni in the female, and the ground 

 colours can be seen at any angle. 



In the male the head appears to contain brownish, yellowish, and 

 black colours ; the fiontal suture is closed. In the female the head is 

 mostly brownish, and the frontal suture is open and black. The eyes are 

 black. The antennae are black, with the basal joints and the first segment 

 of the arista brown. In tlie male the thorax and scutellum aie black; in 

 the female these areas are mostly black, but more or less covered with a 

 white tomentum. Anterioilj- to the t)ansverse suture the female lias the 

 anterior border and sides, and al.'<o two median stripes, covered with a 

 white tomentum, which fui ther coveis the apical quaiter of the thorax 

 and the whole of the scutellum. 



