702 LIFE-HISTORIES OF AUSTRALIAN ODONATA, NO. III., 



We must now turn our attention to the cast-skin of the nymph, 

 which is a most remarkable object, and in many respects quite 

 unlike any other known dragonfly nymph (see Plate Iv., fig.l.): — 



Total length 35 mm., abdomen 23 mm., head 5-5 mm. long by 

 9 mm. wide; width of prothoraK 52 mm., of mesothorax 7'3mm., 

 of metathorax 8 mm. Greatest width of abdomen 10 8 mm. at 

 segmeut 5. Wing-cases 7 mm. long. 



Colour, a nearly uniform dull brown all over; nearly the whole 

 of the upper surface of the head, thorax, legs, and abdomen 

 finely granulate. Head large, of distinct u^schnine form; eyes 

 very large and prominent, postocula?' areas very granulate, rounded 

 behind, but with the margins irregularly wrinkled, and with a 

 small tubercle projecting just behind each eye. Ver^tex large, 

 broadly shield-shaped, the three ocelli set right at the back close 

 to the prothoracic border; antennm wide apart, 2-5 mm. long, 

 seven-jointed, the three basal joints thickened, the four terminal 

 ones thin, longer. (Probably the position of the ocelli and 

 antennae is too far back in the exuviae, owing to the backward 

 shifting of the vertex over the postocular area after transforma- 

 tion); front, clypeus, a.nd labrum very granulate, the latter widest, 

 bordered with a dark line on the lip, carrying a row of tiny 

 close-set pale hairs. Labium very strong and muscular; basal 

 joint very strong and thick, well rounded beneath, and nearly 

 2 mm. through. Mentum fairly flat, but very muscular; almost 

 square, but slightly narrower basally and with the sides slightly 

 curved; very strong and thick, being quite 1 mm. through on 

 each side, lateral edges slightly upcurved and furnished with a 

 iow of very small spines; median lobe only very slightly pro- 

 minent, edged with fine hairs. Lateral lobes carrying a very- 

 large sharply pointed outer tooth, from behind the basal portion 

 of which there arises a large inner tooth, shorter and blunter 

 than the outer one, and possessing a finely serrated inner edge 

 (see Plate Iv., fig. 2). Thorax: prothorax well formed, with 

 a prominent frontal collar and large upper and lower lateral 

 spiny projections on each side; upper and lateral surface entirely 

 granulate except for a small sunken double spot on each side of 



