32 



MEMOIES OF TEE QUEENSLAND MUSEUM. 



rather short chaetae. The oeellar triangle is not very prominent and bears 

 about four pairs of short oeellar bristles. Behind the triangle there is 

 on each side a prominent vertical bristle, with a shorter one adjacent to it. 

 The facial region is practically triangular in outline. The silvery parafrontals 

 do not extend upwards between the eyes except as a thin black line on either 

 side between the frontal stripe and each eye. The characters of the silvery- 

 grey antennffi are shewn in fig. 31. 



Text-figs. 1-4. — Camera lucida drawings to show dorsal colouration. All figs, drawn 

 to same scale. Fig. 1, Musca terrce-regiiKv male; 2, M. terrce-reginoe female; 3, M. hilli male; 

 4, M. liiUi female. 



Thorax {fig. 1) . — When viewed with the light falling from the front 

 the thorax is black and shiny, but when viewed from the opposite quarter the 

 general effect is dark greyish.^ There are four longitudinal stripes, the two 

 outer extending backwards to the sides of the scutellum whilst the two inner 

 extend only to the middle of the scutum. The central silver-grey stripe is 

 rather broader and in individuals of either sex may extend much further 

 forward than the others. The black stripes of each side fuse anteriorly. The 

 posterior half of the midregion of the scutum is rather darker than the other 

 portions. On the anterior part of the scutellum there is a prominent black 

 marking followed by a well-defined smoky patch extending to the hind margin 

 of the scutellum. The chsetotaxy is shewn in fig. 15. 



* The accompanying descriptions of the thorax and abdomen of each species are based 

 on specimens with the head towards the observer and with the source of light opposite the 

 observer. 



