34 DIPTERA OF AUSTRALIA, 



K. First or large basal cell (cellula hasalis prima s. major). 

 L. Second basal cell, or anterior of the small basal cells. 

 M. Third basal cell, or posterior of the small basal cells. 

 N. Anal or axillary corner of the wing (angulus analis s. axil- 

 laris. 



0. Alar appendage (alula). 



Observations. 



E. Cells here of the utmost importance. When d and e are 

 simple, there is therefore only one sub-marginal cell ; but when e 

 has t, we count two cells, an anterior and a posterior one ; when 

 < of e is also connected with d hy a, transverse vein, the number of 

 submarginal cells amounts to three ; that one formed by the inner 

 part of the anterior submarginal cell is called the anterior sub- 

 marginal cell ; when t oi e takes the form of a transverse vein to 

 d, only an anterior and an exterior submarginal cell are dis- 

 tinguished. 



F. Usually subject to no partition, but sometimes closed before 

 reaching the margin. 



G. Frequently divided by the presence of u, and this occurs 

 whenevery emits a hind branch before its end. When G and I 

 ai'e united in consequence of the absence of k the cell thus formed 

 retains the name of G. 



1. This is one of the most important cells belonging to the first 

 section of the posterior part of the wing. When p is wanting, L 

 is considered part of I. When ti is present, sometimes the part 

 of k before or behind it is wanting, then I is regarded as anteriorly 

 or posteriorly opened, as the case may be. 



K, L, and M. The first is generally the longest, and the three 

 are usually spoken of as " one large and two small basal cells," 

 but when g is stretched longitudinally so that M joins the border, 

 or it is distinguished from L by a much gieater length, though 

 closed, M is termed the anal cell {cellula analis). 



