194 MK. R. J. TILLYARD ON THE RECTAL BREATHING-APPARATUS 



25. Sadones, J. 1896. — L'appareil digestif et respiration larvaire des 



Odonates. La Cellule, xi. pp. 273-324, 3 plates. 



26. Scott, D. D. 1905. — The Distribution of Tracliese in the Nymph of 



Platliemis lydia. Biol. Bull. ix. no. 6, pp. 341-354. 



27. SucKOW, F. W. L. 1828. — Respiration der Insecten, insbesondere liber 



die Darm-Respiration der u^'Esclina grandis. Eisenach, Zeitschr. 

 herausg. von Heusinger, Bd. ii. pp. 24-49, t. 4. 



28. Swammerdam, J. 1737-38. — Biblia Naturae, Lat. a Gaiibio, Leydse. 



EXPLANATION OF THE PLATES. 

 Plate 18. 



(Simplex and Implicate Types. Photomicrographs.) 

 Fig. 1. Austrogomphus ochraceus, Selys. Undulate Simplex Gill, from full-grown larva. 



2. Hemiqomplius heteroditus, Selys. Papillate Simplex Gill, from nearly full-grown 



larva. 



3. Austroceschna multipunctata, Martin. Implicate Duplex Gill, fi'om full-grown larva. 



4. Dendroce&clina conspersa^ Tillyard. Ditto. 



(All figures x 60.) 



Plate 19. 

 (Foliate Types. Photomicrographs.) 

 Fig. 6. jEschna brevistyla, Ramb. Normal Foliate Gills, from anterior portion of gill-basket 

 of a lavva about the lOtli iustar. 



6. j^schna brevistyla, E,amb. Ditto, from posterior portion of gill-basket of same larva. 



7. Anax papuensis, Burm. Papillo-foliate Gills, from larva at 8th instar. 



8. Anax papuensis, Burm. The same, seen in profile, from larva at 7th instar. 



(All figures X 60.) 



Plate 20. 



(Lamellate Types. Photomicrographs.) 

 Fig. 9. Metathemis guttata, Selys. Lamellate Gills, from full-grown larva. 



10. Synthemis macrostigma, Selys. Ditto. 



11. Austrocordulia refracta, Tillyard. Ditto. 



12. Semicordulia tau, Selys. Ditto. 



(Fig. 10, X 76. Figs. 9, 11, 12, x 60.) 



Plate 21. 



(Miscellaneous Photomicrographs.) 



Fig. 13. Orthetrum caledonicu7ii, Br. Lamellate Gills, from full-grown larva, (x 60.) 



14. Ortlietrtim caledonicum, Br. Ditto. ( x 16.) 



15. jEschna brevistyla, Ramb. Normal Foliate Gills, from full-grown larva (posterior 



portion of gill-basket). (X 16.) 



16. Ana.v papuensis, Burm. Papillo-foliate Gills, from full-grown larva. In profile. 



(X16.) 



17. Austrogom2)hus ochraceus, Selys. Portions of two holobranchs, to sbow cross-folds. 



( X 16.) Compare text-fig. 2. 



