662 DIPTERA OF AUSTRALIA, 



1. The position of the head, which is placed less deep in the 

 prothorax. 



2. The shape and character of the antennte. 



3. The less high and less acclivous metathorax. 



4. The less elongated coxse. 



5. The strongly developed holding forceps of the ^. 



6. The shorter sub-marginal (first longitudinal) vein. 



7. The medial vein (the portion of the second longitudinal 

 behind the cross-vein) which is close to the sub-marginal (first 

 longitudinal) vein and nearly always running parallel with it. 



8. The fork (of the third longitudinal vein) which is always 

 long-stalked, and generally coming from the middle of the medial 

 vein (the portion of the second longitudinal behind the cross- vein). 



As far as the small number of Australian species known to me 

 are concerned, the system employed by Winnertz has been found 

 perfectly serviceable; it only remains to be seen what new divisions 

 fresh forms may require, but it appears to me probable that very 

 little diversity, if any, will be found, judging from the general 

 conformity of those I now describe. However, from my necessa- 

 rily limited acquaintance at present with the totality of our 

 species, there is little need for me to give expression to any 

 views on the distribution of the group. 



CHARACTERS OF THE FAMILY. 

 The Transformations. 



I. Larva. 



The larva is slender, cylindrical, smooth and shining, more or 

 less translucent, white, pale yellow or citron-coloured, and com- 

 posed of 13 segments. The head is considered the first segment, 

 the three following segments represent the thorax, and the nine 

 remaining constitute the abdomen. Stigmata scarcely visible, 



