96 LIFE-HISTORIES OF AUSTRALIAN ODONATA. iv. 



fore, probable (though not absolutely proved, for these 

 smaller larvae might be capable of extremely rapid develop- 

 ment) that the imago emerges in the second year from the 

 laying of the egg. 



I have not given a drawing of the mature larva, since the 

 drawing of the exuviae*, in my former paper, gives a fairly 

 good representation of it. The main difference is, that the 

 living larva appears slightly shorter and thicker, and the 

 wing-cases are, of course, placed much more flatly along the 

 abdomen, the hind-wing a! most completely covering both the 

 fore-wing, and the first four abdominal segments. In con- 

 clusion, I should like to express my very sincere thanks to 

 Mr. C. Gibbons, who so kindly accompanied me on my ex- 

 pedition to Medlow, and by whose help this most interesting 

 larva was discovered. 



EXPLANATION OF PLATE VII. 



Fig. L — Diagrammatic section of portion of swamp at Medlow, Blue 

 Mountaics, N. S. Wale.s (scale jh), showing : — A, B, clumps of 

 sedge; C depression or water-hole; Ej, a^, ag, bj, bo, openings of 

 Petalura channels; X, X positions of larvse of Synthemis macros- 

 tigma ; Y, Y positions of larvie of Argiolestes grisea. 



Fig. 2, — Teeth of gizzard of Petalura gigaiUea larva (No. 1) (mucli enlarged). 



Fig. 3. — Teeth of g\zza.vd oi peta/tira gigantea laivsiCNo. 2) (much enlarged). 



Fig.4. — a, h, c, Teeth of the fifth, sixth and eighth fields of No.2 gizzard, 

 still further enlarged to show chitinisation of fields around teeth. 



rig.5. — End of abdomen of female larva of P. gigantea. R, rectum — I, I, 

 involucres of imaginal appendages. 



Fig. 6. — Ditto, with the three caudal plates spread open, showing fringe of 

 hairs. 



* These. I'roceefliiigs, 1909, pi. .\xiv. 



