Miller. — The Diptera Fauna of New Zealand. 289 



Art. XXXI. — Material for a Monograph on the Diptera Fauna of 

 New Zealand : Part II, Family Syrphidae* 



By David Miller, F.E.S., Government Entomologist. 



[Read before the Wellington Philosophical Society, 27th October, 1920 ; received by 

 Editor, 31st December, 1920 ; issued separately, 8th August, 1921.] 



Plates XLVII-LII. 



Owing to the fact that some four years ago the greater part of my 

 collection of New Zealand Diptera was accidentally destroyed, I have 

 not until recently had sufficient material at my disposal upon which to 

 publish a regular series. It has in four years been possible, however, 

 to get together a collection very nearly as complete as the original one, 

 which represented the work of ten years, such rapid reconstruction being 

 for the most part due to those able entomologists Mr. G. V. Hudson, of 

 Wellington, Mr. E. Clarke, of Dunedin, Mr. J. R. Harris, of Ohakune, 

 and Mr. J. W. Campbell, of Christchurch, who have generously presented 

 extensive collections from various parts of the Dominion, not only replacing 

 many of the species destroyed, but also bringing to light many new 

 forms. The preparation of this paper was also simplified by the kindness 

 of Mr. R. Speight and Mr. G. Archey, of the Canterbury Museum, in 

 placing at my disposal the late Captain Hutton's types of New Zealand 

 Diptera. The invaluable photographic illustrations are the excellent work 

 of Mr. E. B. Levy, of the Government Biological Laboratories. 



Since the publication of Part I, which dealt in part with the Stratio- 

 niyidae, further representatives of that family have been obtained and 

 will eventually appear as a supplement to Part I. 



The Syrphidae may be characterized as follows : Eyes moderately or 

 densely pilose, sparsely haired or bare, those of the male holoptic at a 

 point or more completely, or dichoptic, in which case they may be very 

 much approximated or more widely separated ; when dichoptic the frontal 

 orbits may be parallel on upper half but divergent on lower, being thus 

 angulated (fig. 68) ; in many cases there is a transverse furrow on the 

 front connecting the orbital angulation. In profile the eyes may descend 

 almost to the oral margin, thus practically eliminating the cheeks, or be 

 much shorter, while in some cases they are comparatively small. The 

 ocellar triangle is of varying shapes and sizes, sometimes, for example, 

 being more or less round and reaching from eye to eye, or long and 

 triangular reaching well on to the front ; the ocelli well developed. Front 

 varying in width according to sex, clothed with pile, with longer or shorter 

 dense or scattered hairs, or altogether bare ; it may be smooth, trans- 

 versely wrinkled, or grooved medio-longitudinally. Antennae shorter or 

 longer, the 3rd joint oval or orbicular (fig. 14) ; more or less rectangular, 

 or elongate (fig. 6) ; arista dorsal in the known New Zealand species, bare 



*Part I in Trans. X.Z. Inst., vol. 49, p. 172 (1917). 

 10— Trans. 



