58 MR. K. J. TILLYARD : LIFE-HISTORIES AND 



appear a dull black, it is worthy of note that mature males when freshly 

 captured have a very delicate pale grey-blue pattern, unlike any other 

 dragonfly known to me. The name " atrata " therefore is scarcely a fortunate 

 one, especially as A. anacantha is, in point of fact, a very much blacker 

 species when alive. 



Genus 3. Noto^schna*, n. g. (Plate 4. fig. 7.) 



Characters as in Austrooischna (restricted), but with the following 

 important differences : — 



Front large, rounded and swollen, standing well up above level of eyes. 

 Wing-memhrane very strong, with thick border. Neuration very strong and 

 open. In the series of antenodal cross-veins, tiie first and fourth in the fore- 

 wing and the first and third in the hind-wing are complete and triangularly 

 thickened, and the more distal of the two stands close up to (or even^ in the 

 hind-wing, exactly at) the level of the arculns ; in Austrocesclma the corre- 

 sponding cross-veins are the first and fifth (wltli few exceptions), and this 

 latter vein is furtlier from the arculus. Triangle of hind-wing distinctly 

 shorter than that of fore-wing, usually only two-celled in male, il/4 less 

 waved than in Aiistroceschna, running jn'actically in a single very flat curve 

 for its wliole length. Sectors of arculus arising separately at about its middle 

 (in Aiistroa^schna they arise closer and lower down). j\leml>ranule fairly 

 large. Legs very large and strong, with large tarsal claws. Female with 

 dentigerous plate under segment 10 obsolescent, but with a very remarkable 

 strong spine at the dorsal end of 10, above and between the anal appendages. 

 Ovipositor much reduced (Plate 9. figs. 13-14). 



Larva remarkably spiny, with small dorsal hooks on 3-9, large lateral 

 spines on 5—9, short spiny superior appendage and enormous spined inferior 

 appendages. Labium with smooth, narrow^ rounded inner lobe. 



Type : Austroa'schna sagittata, Martin. 



This remarkable diagonfly stands out as by far the most highly specialized 

 of our (mtogenic Australian ^Fschnince. It may be regarded in many 

 respects as a cseuogenetic offshoot from the main Aiistroceschna-line quite 

 comparable to Anaaa in relation to the main ^Fschna-Wne, though the 

 Gsenogenesis has not proceeded quite so far. In the specialization of its larva 

 it far outruns any other iEschnine form known to nie (except, perha})S, 

 TelepJdebia). As Martin has already very accurately described both sexes f, 

 I will only add a few important points, and give a full description of the 

 larva and a few notes on the life-history. 



Imago. — The large frooit is dark brown to black all over except for a 



* Greek Noros-, tlie South Wind. The prefixed Noto- and Ausfro- may conveniently be 

 used to denote purely Australian genera. Before the " as " of -(sschna the " '' may be 

 retained for euphony. 



t Martin, ^Eschnines, Coll. Selys, fasc. xix. p. 236. 



