DESCRIPTIONS OF AUSTRALIAN ^SCHNINiE. 45 



metatliorax 4*5 X 6 mm., irregular, with fairly prominent lateral tubercles ; 

 iving-cases 6 mm., parallel. Legs short, fairly strong, much spotted vvith 

 pale brown on a black or dark brown ground-colour ; femora regular, not 

 much flattened. Abdomen. — Elongate-oval, well arched above, flattish 

 beneath, 3 mm. wide at 2, then vs-idening to 7 (7 mm. wide), then curving in 

 to 2*5 mm. width at 10. No dorsal spines. Strong lateral spines on 6-9, 

 those of 6 smallest, the others increasing to 9. Appendages. — Superior 

 short, 1'3 mm.^ depressed, truncate, carrying at its truncated tip two small 

 sharp outer teeth and two blunt median teeth, close together. In the ^ the 

 involucre of the inferior imaginal appendage overlies it as a flat triangular 

 projection ; in both $ and ? the involucres of the superior imaginal 

 appendages lie on each side of it as fairly straight and pointed spines, 

 I'l mm. Inferiors 2*5 mm., broad-based strongly triquetral spines, very 

 sharp, with slightly incurved tips. In the living larva these spines can 

 all be ])ressed together to form a powerful weapon of defence (Plate 7. 

 figs. 3, 15). Ovipositor of ? nymph of medium size, reaching just bejond 

 end of segment 9. 



L a r V a 1 T y p e s.— S ? , Coll. Tillyard. (Heathcote, N.S.W., April 10th, 

 1909.) 



The perfect insect is exceedingly beautiful on the wing, its large glowing 

 emerald eyes and the numerous bright green spots on its thorax and abdomen 

 giving it a very striking appearance. It has already been fully described 

 both by M. Rene Martin and myself (Proc. Linn. Soc. N.S.W. xxxi. 

 (1907) p. 729). Phylogenetically, it seems to hold the same relationship to 

 Aiistroa'schna that Telepldehia does to Austropldehia. There is no doubt 

 that the " aphantochromes '•* ;ire more archaic than the " hylochromes,'' 

 and that the particular line of specialization of the latter has led to their 

 holding, in Australia, the dominant position attained in a somewhat similar 

 manner in the Holarctic Region by JEschna, itself an archaic genus. 

 But there can be little doubt that this development has been mainly due 

 to the absence of competition with the larger and stronger species of 

 ASschna, rather than to any intrinsic superiority ; for our only species 

 of the latter genus, ^. hrevistyla, is more widelv spread and commoner 

 than any of the " hylochromes," and its voracious larva takes heavy toll 

 on the latter wherever they occur together. 



Grenus 2. Austro^eschna, Selys (a me restrictum). 



Neuration open ; median space free, submedian and basilar spaces with a 

 few cross-veins. Us forked v\ell before level of pterostigma ; Rspl separated 

 from lower branch of fork by a single row of cells. M^ distinctly waved in 

 its distal half so as to increase the intervening cell-rows between it and M^ 



