1968] 
Carpenter and Richardson — Megasecoptera 
309 
aquatic environment. Third , the origin and original function of 
insect wings must now be examined with this new evidence in mind; 
the possibility of functional movement of the wing pads, for one 
reason or another, needs to be considered further. Fourth, it is now 
clear that the beak was as fully developed in the nymphal forms as 
in the adults of the Megasecoptera and also that the beak in this 
order was basically like that in the Palaeodictyoptera. It is a virtual 
certainty that the beaks of the palaeodictyopterous nymphs were also 
like those of their adults. Since the nymphs of both of these orders 
almost certainly fed on the same food as the adults and since the 
adults were clearly terrestrial and aerial, the possibility of the nymphs 
having been aquatic seems very remote. The complete absence in the 
mischopterous nymphs of tracheal gills, which are very well developed 
in the Permian mayfly nymphs (personal communication, J. Ku- 
kalova), is another strong indication that the megasecopterous nymphs 
were not aquatic. 
References 
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Carpenter, F. M. 
1948. The Supposed Nymphs of the Palaeodictyoptera. Psyche, 54: 65- 
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1951. Studies on Carboniferous Insects from Commentry, France. Part 2. 
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1911. New Paleozoic Insects from the Vicinity of Mazon Creek, Illinois. 
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