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AUSTRALIAN BLEPHAROCERIDAE. 



(ORDER DIFTERA). PART 1 :— DESCRIPTION OF NEW SPECIES. 



By R. J. Tillyard, MA.. Sc.D. (Cantab.), D.Sc. (Sydney), C.M.Z.S., F.L.S., 

 F.E.S., Entomologist and Chief of the Biological Department, Cawthron Institute, 

 Nelson, N.Z. 



(With two Plates and seven Text-figures.) 



The Blepharoceridae or Net-veined Midges are an archaic family of Neino- 

 eerous Diptera highly specialised for life in all stages on or about waterfalls and 

 cascades. The eggs are laid singly on the faces of rocks permanently wetted 

 with the spray of the falls, and the larva passes its whole life either in the same 

 situations, or actually sticking to the rocks over which the water rushes. In 

 order to be able to do this, it is provided with a set of six conspicuous mid- 

 ventral suckers. The pupa is a black, oval object, attached firmly to the rock 

 beneath the rushing water by three pairs of pads on its flat ventral surface, 

 and breathing by means of two conspicuous prothoracic respiratory processes, 

 each formed of four lamellae. The imagines have very long, slender hindlegs, 

 and cling to the wet rocks with all six legs spread widely out. Their wings are 

 held out at right angles to the body and in line with one another; this habit 

 enables the collector at once to distinguish a.Blepharocerid from various forms 

 of Tipulidae which frequent similar situations, but which always rest with the 

 wings folded down the abdomen. The secondary net-veining (Text-fig. 1) which 

 is peculiar to this family has nothing to do with the true venation, but represents 

 the creases formed in the wings while folded up in the pupa. It seems to have 

 arisen because of the necessity for the imago to emerge with the greatest possible 

 speed in order to avoid being swept away by the rushing waters; consequently, 

 the wing has to become fully developed within the pupal shell before the imago 

 discloses itself, and these secondary creasings are the result. Other characters of 

 importance for the family are the frequent occurrence of boloptic eyes, and of 

 eyes divided transversely by a non-facetted line or band into two portions, the 

 upper of which has facets of a larger size and a different colour from those 

 of the lower, thus closely resembling the similar eyes to be found in Ascalaphidae 

 and certain Dragonfiies. The mouth-parts are formed for piercing, particularly 

 in the case of the females, which are furnished with long spear-like mandibles, 

 absent in the males. The hypopygium of the males resembles that of Mecoptera 

 and of certain Tipulidae, there being no secondary rotation of the terminal ter- 

 gites and sternites through 180°, as in Psychodidae and Culicidae. The so-called 

 superior appendages are not true appendages, but processes from the ninth ter- 



