I7O ENTOMOLOGICAL NEWS [Apr., '17 



Two of these papers 1 deal with wing tracheation, and, like 

 the others, are based on a large first-hand accumulation of 

 facts. Especially valuable is the contribution to the knowl- 

 edge of the development of the Cordulinae, a subfamily that 

 is represented in Australia by many remarkable forms. But 

 all the groups of the available fauna have been extensively 

 drawn upon. 



Tilly ard's studies of tracheation extend and entirely cor- 

 roborate my own 2 in so far as facts are concerned ; but he of- 

 fers a different interpretation of two matters: (i) the anal 

 veins of the Anisoptera; (2) the radial sector of the Zygop- 

 tera. I desire to restate my views concerning these in the 

 light of the new evidence and arguments he has produced. 



Tillyard's interpretation of the anal region of the Anisop- 

 teran wing differs but little from my own. He found, as I 

 did earlier, that the anal trachea is closely approximated to 

 the cubital for a distance and then descends through an ap- 

 parent cross vein ; then bends again sharply outward and fol- 

 lows thereafter the direct course of the anal vein. He pro- 

 poses to call the apparent cross vein the "anal crossing," and 

 this I consider an excellent descriptive term and better than 

 "basal cubito-anal cross vein," whether it were originally a 

 cross vein or not ; in one instance at least he has shown it is 

 not the most basal of the series of cubital-anal cross veins. 

 Tillyard would call the vein that forms about the conjoined 

 portion of the cubital and anal tracheae Cu+A ; and I see no 

 serious objection to this, especially since he then disposes of 

 the vein hitherto known as the anal by a device so little incon- 

 venient as merely labeling it A" 3 It was not merely the thought 



Tillyard, R. ]. On some problems concerning the development of 

 the wing venation of Oclonata. Proc. Linn. Soc. N. S. Wales 39: 163- 

 216, 3 plates, 1914. 



Tillyard, R. ]. On the development of the wing venation in Zygop- 

 terous dragonflies with special reference to the Calopterygidae, Proc. 

 Linn. Soc. N. S. Wales 40: 212-230, 6 text figures, 3 plates, 1915. 



2 Needham, J. G. A genealogic study of dragonfly wing venation. 

 Proc. U. S. Nat. Mus. 26: 703-764, 14 plates, 44 text figures, 1903. 



3 In his studies of tracheation of the Chrysopidae (Proc. Linn. Soc. N. 

 S. Wales 41 : 221-248, 1916), Tillyard also uses this simple device most 

 opportunely to obviate a cumbersome terminology when apparently 

 simple and direct veins are variously compounded. The condition there 

 pointed out was previously noted by McClendon (Ent. News 17: 120, 

 1906). 



