8 Mil. R. J. i'lLLYAEl) : LtFE-HISl^OElES ANC 



the growing parts of the female ovipositor, and may be so large as to extend 

 right across the ninth segment and even on to the tenth. In descriptions of 

 exuviae, it will simply be called the ovipositor for brevity. For brevity also^ 

 I have adopted the plan of describing male and female larvse or exuvise 

 together, ending with separate descriptions of those sexual outgrowths in 

 which they differ. 



In the study of the imagines, I have not included a detailed account of the 

 genital fossse of the males, reserving these, together with some larval 

 structures (the gizzard and rectal tracheoles), for future treatment. All the 

 Australian forms are easily separated without recourse to this line of study, 

 which is, however, of great importance in groups — such as the majority of 

 the Lihellulince and the Holarctic species of the genus ^schna — in which 

 the anal appendages of the male are not so clearly differentiated in the 

 various species. It may be mentioned, however, that the Australian members 

 of the second tribe, Brachytrini, nearly all possess the structures of the 

 second sternite in very similar form to that already described for Boyeria by 

 Walker, with the spines of the anterior lamina not so well developed as in 

 the j^sclinini. The reduction of the ovipositor in Notoceschna has run parallel 

 with a corresponding alteration in the details of the genital fossa of the 

 male, which I have therefore thought it advisable to figure (PL 9. fig. 15). 

 Good drawings of the various parts that are sunk deep into the fossa can 

 only be obtained by cutting away the margins of the second tergite ; and, 

 owing to their brittleness, the investigation of the parts in detail is best 

 made by preparations from freshly killed specimens. This I have not yet 

 been able to undertake. I have, however, figured and described the fossa of 

 Austropetalia j?atricia, which is of somewhat more general interest. 



A list of the material studied is given in an appendix (Appendix A). 

 Mr. Herbert Campion's description of a new subspecies of Telephlebia 

 godeffroyi, Selys, is attached, by his kind permission, as Appendix B, and 

 completes the study of this interesting genus. I have also given two com- 

 parative tables for reference; the h'rst, inserted before the description of 

 new species of Austroci'schna (p. 48), gives the main points of difference 

 between the twelve known species of that genus ; the second (p. 75) shows 

 the chief differences in the known larvse of Australian ^^schnina;, and gives 

 the main results of the detailed larval studies at a glance. 



Phylogeny and Geographical Distrihution. 



Walker's latest scheme for the classification of the yiHschnince, based on 

 those of Karsch and Needham, but with certain amendments, is an excellent 

 one from a phylogenetic standpoint. With his view of Anax and Hemianax 

 as a direct csenogenetic offshoot from an archaic ^schna-ioviw I strongly 

 agree ; for my studies of the larvse of Anax and ^sclina only tend, in my 



