188 
Dipterous Larvae 
conspicuous dense chitinous network, resembling very much, in arrange¬ 
ment the appearance of a mycelium of some fungus growing on culture 
medium, or the “ picture ” produced by the cathode electric brush- 
discharge on a photographic plate. It is a type unlike anything else 
that has been described, or found in any of the specimens yet examined, 
and in the Oestridae there seems to be the greatest difference in the form 
of the stigmata, each genus apparently having its own individual type. 
In conclusion I should like to thank Dr Wheeler and Mr Brues for 
their help and suggestions, which at all times they have been so ready 
to give ; and Drs Ernst and Wolbach, of the Harvard Medical School, 
for their courtesy in permitting me to use the most excellent photo- 
micrographic apparatus that they possess, without the use of which I 
could have made very little of these difficult subjects for photography. 
DESCRIPTION OF PLATES XIV XVI. 
Note : magnifications given are only approximate. 
Fig. 1. Posterior stigmata of Lucilia caesar, x 50 diams., showing both plates in situ. 
Fig. 2. Posterior stigmata of Lucilia caesar, x 140 diams., showing one stigmal plate. 
Fig. 3. Posterior stigmata of Cynomyia cadaverina, x 50 diams., showing both plates 
in situ. 
Fig. 4. Posterior stigmata of Cynomyia cadaverina, x 150 diams., showing one stigmal 
plate. 
Fig. 5. Posterior stigmata of Calliphora vomitoria, x 40 diams., showing both plates in 
situ. 
Fig. 6. Posterior stigmata of Calliphora vomitoria, x 120 diams., showing one stigmal 
plate. 
Fig. 7. Posterior stigmata of Musca domestica, x 75 diams., showing both plates in situ. 
Fig. 8. Posterior stigmata of Musca domestica, x 225 diams.. showing one stigmal plate. 
Fig. 9. Posterior stigmata of Gastrophilus equi, x 30 diams., showing the single stigma. 
Fig. 10. Posterior stigmata of Gastrophilus equi, x 60 diams., showing the bar system in 
greater detail. 
Fig. 11. Posterior stigmata of Gastrophilus equi, x40 diams., showing the bar system on 
the membrane. 
Fig. 12. Posterior stigmata of Gastrophilus equi, x 100 diams., showing the bar system on 
the membrane in greater detail. 
Fig. 13. Posterior stigmata of Oesiris ovis, x 30 diams., showing both plates in situ. 
Fig. 14. Posterior stigmata of Oestris ovis, x 80 diams., showing one stigmal plate. 
