598 DIPTERA OF AUSTRALIA, 



the vein which in Platyura, Macrocera, etc., has the little branch 

 at the end (an instance to the contrary in Beschr. Eur, Dipt., I., 

 p. 16, in the description of Macrocera fastuosa must be a lapsus). 

 The two veins forming the large forks (klmn and ajjqr of your 

 PI. 32, fig. 17*) Loew would call the fourth and fifth veins (and 

 Schiner would use the equivalent terms of Discoidal-ader and 

 Postical-ader). Compare for instance Loew, Century IX., p. 139, 

 No. 18, Scmphila ohtruncata, "primum vense longitudinalis g-Mar^ce 

 segraentum a prime quinke segmento longitudine paulo superatur." 



"Therefore in your paper on Mycetophilidse wherever you say 

 second longitudinal vein, it should read third ; and wherever you 

 have thi7'd it should be fourth and so on, to the end. The names 

 of the cells should also be changed. The Jirst posterior cell is 

 always the cell which has the small cross-vein at the base, there- 

 fore your cell F. Your G is the second posterior. C is the 

 anterior, H the posterior basal cell ; the latter here reaches the 

 margin of the wing. 



" In the Mycetophilidfe you hit upon one of the most diificult 

 cases, because even Schiner's figure explains the matter incom- 

 pletely. He has no name for your cell I (within the iovk. pqr^. 

 In reality it is the fourth posterior cell ; but as there is no third 

 posterior cell in this case (owing to the extent of H, the posterior 

 basal cell) it may perhaps be more expedient not to name this cell, 

 but, in case of necessity, to describe it as tlie cell included within 

 the fork of the fifth longitudinal vein. Schiner may have meant 

 it so in omitting to name this cell." 



Fam. MYCETOPHILID^. 



Lygistorrhina, gen.nov. 



Head small, rounderl, narrower than the thorax ; exserted from 

 the thorax ; front rather narrow. Eyes large, approximate beneath. 

 Ocelli three, arranged in a small triangle on the vertex, the ante- 

 rior one very small. Proboscis \eYj long and slender, rather more 



* P.L.S.N.S.W., (Ser. 2), Vol. III., 1888. 



