248 STUDIES IN AUSTRALIAN NEUROPTKRA, iii. 



Draofonflies. Alternation of straight and weaklv zie-zaffced 

 longitudinal veins is a very advantageous and specialised arrange 

 ment, and is developed to perfection in Chrysojya, where R is 

 straight, Rs zig-zagged, M' straight and Cu' zig-zagged. 



We may conclude, then, that Mesochrysopa stood very near, 

 if not actualh' upon, the line of descent of our recent Chryso- 

 pidrc.. As this is an Upper Jurassic form, the rise of the true 

 Chrysopidfe probably began in the Cretaceous. About this time, 

 or perhaps in the Eocene, our present Aphides became developed 

 (man)' species are known from the Lower Oligocene). As the 

 Chrysopid larvte feed upon Aphides and similar insects, the 

 evolution of the two groups must have proceeded step by step 

 together, until the present intimate association became fuUv 

 established. 



EXPLANATION OF PLATES X., X. his. XI. 

 Plates x.-x. Iiis (Tran.spareney). 

 Tlie iniaginal venation of Ckrysopa fiignata Walker, is shown, much 

 enlai'ged. in black, on Plate x. Superimposed upon it, in red, on the 

 transparencj', is a diagrannuatic scheme of the pupal tiaclieation, to 

 enable the reader to trace the intricate formation of the pseudo-media and 

 pseudo-cubitus. 



lA, 2A, 3A, the three anal veins — B1-B4, the four Banksian sectors 

 ( — 87-8,0) — /*, upper, and h' , lower Banksian cells— C, costa — Cu, cubitus 

 — Cuj, its upper, Cu,, its lower branch — Cu', pseudo-cubitus — cu, cubital 

 cell — fuf, cubital fork — cuf\ second cubital fork — df, distal forks — (j, 

 inner, //', outer series of gradate veins — leu, intra-cubital cell of hindwing 

 icux-icu-i, the three intra-cubital cells of forewing — ///i], iin_, first and 

 second intra-median cells — M, media — M,, its upper, M.,, its lower branch 

 — M', pseudo-media — m^-m^, median cells — ma, median arculus — mf, 

 median fork — ml, median loop ( = "divisory veinlef of Banks) — p, pos- 

 terior cells — pt, pterostigma — R, radius — rf, radial fork — Rs, radial sector 

 — 8^-81 0, its branches — Sc, subcosta — w.f, subcostal cross-vein — t, minute 

 triangle ( — remnant of first upper Banksian cell in hindwing) — x, false 

 origin of Rs in hindwing. 



Plate xi. (Photomicrographs). 

 Fig. 1. — Tracheation of pupal wings of ChryAopa xijnata Walker, ( x 40). 



Pupa one day old. 

 Fig. 2. — Forewing and a small portion of hindwing of same, ( x 66). 

 Fig.3. — Hindwing of pupa of Chrympa A, ( x 27) to show rucking of the 



wing. Pupa nearly three days old. 



