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Psyche 
[December 
the latter are always directed anteriorly. As far as I know, there 
is no evidence in any insect ovipositor of hairs directed posteriorly, 
which would presumably prevent the valves from penetrating the 
substrate. 
The male claspers of Palaeodictyoptera have previously been known 
in only one specimen belonging to Stenodictya spinosa (Brongniart) 
(Kukalova, 1970, Pt. Ill, p. 11, fig. 53 , p. 13, 54)* Their 
structure resembles that of the claspers of Permian Megasecoptera 
(Carpenter 1939, p. 31, fig. 2 A) and those of Permian and some 
Recent Ephemeroptera. They are relatively more primitive, however, 
composed of small, equal segments, not unlike cerci, and directed 
towards each other beyond the 9th segment instead of at about the 
middle. In the light of this evidence, the claspers of Dunbaria may 
be regarded as very advanced in structure, actually approaching in 
general respects those of some dragonflies. This circumstance is of 
great interest, since besides the significant similarity of the female 
ovipositor to that of dragonflies, Dunbaria provides the first evidence 
of the similarity of the male genital structures as well. The conver- 
gence of wing structures to dragonflies repeatedly occurs in different 
evolutionary lines of Palaeodictyoptera (Calvertiellidae, Eugereonidae, 
Archaemegaptilidae, etc.). In spite of the closer relationship which 
is indicated between the Palaeodictyoptera and Ephemeroptera, all of 
the evidence, including that of the genitalia, supports the assumption 
of single ancestral stock of all palaeopterous orders. 
Variability of Wings of Dunbaria 
In current studies on palaeodictyopterous wing venation, the sec- 
ondary branching of veins is generally considered to be not a specific 
feature but rather one of individual variability. Much emphasis is 
given by some authors to the level of first branching of main veins, 
especially R and M, and to the widths of wing areas. Little informa- 
tion is known of the individual variability of wing shape and size. 
The following analysis of wing morphology of nine specimens of 
Dunbaria fasciipennis provides some data on this subject. 
The fore wing length ranges from 16.3 mm to 18.1 mm and the 
width from 5.2 mm to 5.8 mm. The hind wing length varies from 
17 mm to 17.9 mm and width from 6.6 mm to 7.6 mm. 
A nterior Margin : It is concavely curved in more or less all wings ; 
this feature in Palaeodictyoptera is often affected by preservation and 
needs to be considered very carefully. Costa: The bandlike broaden- 
ing of C tends to be more pronounced and longer in the larger wings. 
Sc: The length of this vein is variable within the anterior part of 
