1970] 
Kukalova — Palaeo dicty opt era 
39 
at the base of both pairs of wings. There are also present in the 
basal part of the wings (especially if they are long or thin) 
transverse, supporting structures, generally in the form of cuticular 
thickenings, supporting cross veins or dark sclerotized bands. In 
some species there is a deep, oblique furrow crossing the basal 
part of the anal area and forming a line along which the wings 
appear to break readily; the function of this structure is not known. 
The wings are often dark in color, with transverse light bands 
or with small, circular spots in varied patterns of distribution. There 
are also circular, cuticular thickenings on the wing membrane, 
which may have been the site of macrotrichia with a sensory function. 
The precostal strip, bordering the costa for varying lengths, is ser- 
rated in some species, as it is in the existing Odonata. The palaeo- 
dictyopterous wings were apparently consistently hairy, at least 
along the veins; the cross veins, the elements of the archedictyon 
and the wing membrane itself between veins also had hairs in some 
species. Sometimes long hairs formed clusters at the base of the 
wing and along the wing margin (recalling the subimaginal con- 
dition of some mayflies) or on the wing membrane. 
The abdomen was always shorter than the wing but, with few 
exceptions, it was not excessively broad. Often, the lateral parts 
of the tergites of the abdomen were separated from the main part 
of the tergum by a longitudinal suture, resembling in general the 
structure of the lateral lamellae of some mayfly nymphs. In a few 
cases, the tergites were strongly sclerotized. with lateral expansions, 
having oblique ridges along the expanded portions. The females 
had a robust ovipositor, usually curved but not really elongate. 
The general nature of the ovipositor resembled that of the Recent 
Zygoptera and some Anisoptera. The males of at least some Palaeo- 
dictyoptera had short but distinct claspers, apparently segmented, 
and arising from the ninth segment. The aedeagus was paired, at 
least in the few specimens in which this structure was preserved ; 
a similar condition is known in the Protohymenidae of the Megase- 
coptera. Both males and females of the Palaeodictyoptera possessed 
long, robust, multisegmented cerci, approximately twice as long as 
the abdomen. 
Very little is known about the nymphs of the Palaeodictyoptera. 
The evidence, such as it is (Carpenter and Richardson, 1969, p. 309), 
indicates that the nymphs were terrestrial and, like the adults, had 
haustellate mouthparts. The wing pads of the nymphs were held in 
oblique-lateral positions, independent of each other in all stages and 
