IN THE LARV^ OF ANISOPTERID DRAGONFLIES. 195 



Fig. 18. Austrogomphus multipunctata, Martin. Portions of three liolobranchs. (x 16.) 

 Compare text-fig-. 5. 



19. Anax papuensis, Biirm. Three complete holobranchs. ( x 16.) Compare text- 



fig. 9. 



20. Austrocordidia refracta, Tillyard. Portions of three holobranchs. ( X 16.) Notice 



basal pads and absence of pigmentation. 



21. Diplacodes hcematodes, Burm. Portions of three holobranchs. (x 16.) Notice 



basal pads and deep pigmentation. Compare text-fig. 12. 

 (Figs. 17, 18, 19, 21 are photographs of portions of the whole mounts from 

 which the text-figures 2, 5, 9, 12 respectiveljr were also taken.) 



Plate 22. 

 (Transverse sections of Gill-baskets and Basal Pads.) 

 Fig. 22. Austrogomphus dchraceusj^eljs. Diagrammatic, T. S. through gill-basket. ('x46.) 

 2^. ^schna hrevistylu, ~R?avL\) . Ditto. (x 16.) 



24. Coi'dulep/iya pi/c/7ncea, Seljs. Ditto. (x 22.) Only those lamellse 



are shown whose basal pads are actually cut, in this section, nearest their middle 

 lines. The rest are omitted. Contrast fig. 27. 



25. Austrogomphus oc.hraceus, Selys. Much enlarged T. S. through base of gill marked* 



in fig. 22. ( X 305.) 



26. ^sclma brevistyla, Ramb. Much enlarged T. S. through base of gill marked * in 



fig. 23. (X135.) 



27. Cordulephya pygmcea, Selys. Much enlarged T. S. through base of lamellae actually 



cut through near point marked * in fig. 24. (x 220.) 



Hefereuce letters : — 



6p, basal pad; bp (fig. 24), the same, cut farther from its middle line; cf, cross-fold; 

 cm, circular muscle-layer ; DT, dorsal tracheal trunk ; eg, epithelium of gill ; ep, primary 

 efferent trachea ; er, epithelium of rectum ; es, secondary efferent trachea ; es', the same 

 (dotted line), not in the true level of the section; ^, gill-folia; /??/, hypobranchial tissue; 

 lam, gill-lamella; mf, main longitudinal gill-fold; mf (fig. 23), the same, aborted and 

 functionless ; nu\, meganucleus of basal pad; nuo, micronucleus of same ; nu^, nucleus of 

 gill-epithelium; nw^, nucleus of hypobranchial tissue ; mi-j (fig. 27), minute nucleus in basal 

 pad ; pg (fig. 26), highly pigmented gill-epithelium ; R, rectal cavity ; sp, space between 

 gill-walls, above hypobranchial tissue ; tr, trachea; VT, visceral tracheal trunk. 



Postscript, March 1st, 1915. 

 Ontogeny of the GUIs in the Larvce of Lihellulidce. 

 Since the above paper was written, I have succeeded in hatching a number 

 o£ larvse of Diplacodes hcematodes, Burra.j and have studied their gill- 

 formation. Two females of this species were taken while ovipositing in the 

 Greorge's River, Ingleburn, N.S.W., on Feb. 13th last. Each laid a large 

 number of eggs into a tube of water held in the hand. These eggs were 

 placed with sand and debris in water in a Petri dish. In a few hours 

 thej became coagulated together into large masses. Within three days they 

 developed a strong growth of fungus, so that I did not expect them to hatch. 



