54 THE DIPTJIBA.-B&A.CHYCS&A OF TASMANIA. 



the front above the antenna;, and by the third antenna! 

 joint being longer than the first and second together, and 

 broader than either of tnem. In order to determine the 

 validity of these distinctions it is necessary to consider 

 two nearly allied, undescribed species, which undoubtedly 

 belong to the same genus as P. elegans, the species 

 described by von Krobcr. Neither of these two species, 

 one of which occurs in Victoria and the other in Tas- 

 mania, shows any sign of an arching of the front, which 

 would therefore appear to be a specific character only. 

 As to the antennae, both these species agree with /'. de- 

 gam in having the third joint longer than the first and 

 second together, and broader than either of them, though 

 in neither case is the third joint nearly so Large in pro- 

 portion as in that species. In most of the Australian 

 species of Psilocephala, however, the third joint is broadi r 

 than either the first or second, and if not actually longer 

 than, is frequently about the same length as, the two 

 together; indeed the second species occurring in 'fa-mania 

 has antennae hardly differing from those of Psilocephala. 

 Under these circumstances some further distinction 



arv. I would characterize the genus as follows: — 

 Small, delicate, black flies, having the head broader than 

 the thorax, the front bare, the proboscis small and lying 

 close against the lower face; antennae with the third joint 

 longer than the first and second together, and broader 

 than cither of them ; eyes joined or closely approximated 

 in the male, widely separated in the female ; abdomen 

 long and slender; wings hyaline or crossed by distinct 

 black bands, the fourth posterior cell always closed. 



Taking the genus in this sense, it may be distinguished 

 from Psilocephala by the closed fourth posterior cell, the 

 cell being usuallv closed at a considerable distance above 

 the wing margin; from Lonchorhynchus by the small pro- 

 boscis lying close against the face, the smaller size, more 

 slender, shape, and by tin markings of the wings, if pre- 

 Bent, taking the form of clearly-denned black bands. 



I think it doubtful, judging from von Krober's descrip- 

 tion, whether his genus Oldenbergia is really distinct from 

 Parapsilocephala. Also his genus Pseudoloxocera, which 

 is not- recognizable from his description, may possibly 

 belong here. 



The spceies of Parapsilocephala are widely distributed 

 through New South Wales, Victoria. South Australia, and 

 Tasmania. They may be swept from long grass, and arc 

 often common where they occur. 



