44 MR. R. J. TILLYAUD : LIFE-HISTORIES AND 



darting. Every now and then they descend to chase small gnats and flies, 

 and may then be captured with a little luck, though they are very skilful and 

 quick at dodging the net. Later on, in the afternoons, and especially 

 towards the end of May, when they are mature, these insects descend to the 

 creek-bed and fly very rapidly up and down. The females oviposit in May 

 and June, and oven on warm days in July. Their method is to select some 

 old and half-rotted piece of wood dipping into the water, or occasionally a 

 damp mossy rock, on which they settle. They then proceed to lay their eggs 

 one by one into the damp wood or moss. This is done deliberately and 

 'slowly. I have watched a female stay for over twenty minutes in one spot 

 ovipositing. They are, however, extremely watchful, and tlie slightest 

 movement sends them dashing off. 1 never succeeded in catching an 

 ovipositing female, though I have taken them while they were examining 

 suitable nooks and corners for laying. 



Probably the eggs do not hatch until the s[)ring, for in November and 

 December any larvae taken are exceedingly small. The young lar\'a is very 

 hard-skinned, beinj,- absolutely black and very spiny. After an ecdysis the 

 larva is green and delicate for a short time, then rajtidly darkens, and in less 

 than an hour is hard and black again. It lies on twigs, amongst debris, or 

 hiding on the underside of flat rocks. It is very active, and can run rapidly. 

 If handled, its sharp spines can be used with considerable efl'ect, and are, no 

 doubt, a strong defensive weapon against its natural enemies. It is a 

 voracious feeder, attacking other Odonate larvas and even its own species 

 witliout discrimination. Ecdyses succeed one another rapidly during the 

 summer, usually at intervals of a fortnight or less^ according to the supply 

 of food. About the end of February the larva becomes torpid for some days, 

 and the skin is excessively hard and tough. Finally, it emerges by crawling 

 up a stick or stem, usually in the early morning. 



Larva. — The full-grown larva is not absolutely black, but has a ground- 

 colour either of black or very dark brown, very intricately mottled all over 

 with paler brown. 



Total lengtli 30-34 mm.; greatest breadth 7 mm. across eyes and also 

 across segment 7 of abdomen. Head. — 5'5 mm., with prominent eyes, 

 front, and lahrum ; antennw 2 2 mm. a[)art at bases; postocular lobes large, 

 rounded, with a projecting lateral spine on each side, 5'5 mm. apart. 

 Labium. — Mentum 6 mm. long, 4*5 mm. wide distally, narrowing basally 

 and reaching back to between mesocoxse, where it is only 2*5 mm. wide. 

 Median lobe very slightly convexly curved, with a row of short stiff hairs. 

 Lateral lobes with apex truncate, outer angle slightly rounded, inner angle 

 almost a right angle, inner border very finely crenulate ; movable hook 

 strong, curved, 1"2 nun. (Plate 5. fig. 7). T h o r a x. — Protliorax 2 x 4",5 nnn., 

 with prominent humero-lateral spines, and below them, on each side, two 

 sublateral spines or prominences close together (Plate 6. fig. 3). M.eso- and 



