BY T. H. JOHNSTON AND M. J. BANCROFT. 203 
TEXT-FIGURES 15-20. 
Allfigures drawn to the same magnification. 
Fig. 15. Anterior spiracle of mature larva of M. vetustissima. 
Fig. 16. Anterior spiracle of mature larva of M. australis. 
Fig. 17. Posterior spiracle of mature larva of M. vetustissima. 
Fig. 18. Posterior spiracle of mature larva of M. australis. 
Fig. 19. Posterior spiracle of second instar of MW. vetustisstma. 
Fig. 20. Posterior spiracle of larva (second instar) from uterus of 
M. australis. 
TEXT-FIGURES 21-26. 
Fig. 21. Posterior spiracles of larva of M. vetustissima moulting from 
2nd to 3rd instar, showing the two sets of spiracles, the 
larger developing below those of the second instar which 
are about to be thrown off. 
Fig. 22. Posterior spiracles of first larval instar of M. vetustissima. 
Figs. 21 and 22 are drawn to the same scale. 
Fig. 23. Posterior spiracle of 24 hours old larva of M. australis 
showing new spiracles of third instar developing below 
those of the second instar which are about to be cast off. 
Fig. 24. Highly magnified view of two process of the anterior spiracle 
of a mature larva of M. australis. 
Fig. 25. Puparium of WM. australis. 
Fig. 2 
26. Puparium of M. vetustissima. 
LITERATURE REFERRED TO. 
CLELAND, J. B.—Insects and their relationship to disease in man in 
Australia. Trans. Austr. Medical Congress (Sydney 1911), 9, 
1913, pp 548-570 (see pp. 562-569). 
Froceart, W. W.—Australian Insects (no date—1907), 450 pp. 
Frocearr, W. W.—Sheep-Maggot Flies. Farmers’ Bulletin No. 95. Dept. 
Agric. N.S.W., 1915 (52 pp.) 
Froeearr, W. W., and Froceatrr, J. L.—Sheep-Maggot Flies, No. 2. 
Farmers’ Bulletin No. 110. Dept. Agric. N.S.W., 1916, 30 pp. 
GrawAM-SmitnH, G. S.—Flies in relation to disease. Non-blood-sucking 
flies. Camb. Univ. Press, 1914. 
Hewitt, C. G.—The House Fly. Camb. Univ. Press, 1914. 
Macquart.—Dipteres Exotiques, Tome II, part 2, 1842. 
Patron, W. S., and Craae, F. W.—A Text-book of Medical Entomology 
1913. 
Watker, F.—List of the specimens of Dipterous Insects in the collection 
of the British Museum, part 4, 1849. 
