14 
Psyche 
[March 
being a male and lobata a female; but since there is no information 
at all about the sexual dimorphism in the Palaeodictyoptera, I con- 
sider it preferable to retain Brongniart’s spinosa as a distinct species. 
Stenodictya spinosa represents the only male known of the Com- 
mentry Palaeodictyoptera with claspers preserved. A study of them 
under glycerin has added some further details. They are much more 
primitive than those of the Permian Megasecoptera (Carpenter, 
1 939) and of the Permian and Recent Ephemeroptera. In both of 
these latter orders, the claspers are jointed at about the middle. The 
Palaeodictyoptera is the only known order in which the claspers 
are directed towards each other beyond the basal segment, which 
is slightly larger than the following ones. 
The following account is based on specimen 22-2: Fore wing 
length 61 mm, width 13 mm. Anterior margin strongly convex 
proximally, very slightly concave at about mid-wing; posterior 
margin slightly concave from MP to CuP. Apical part narrowed. 
Subcostal area broadened, narrowing abruptly towards the base. 
Rs with 6 branches, the first branch forked; anal area large with 
6 veins, two of them forked. Hind wing: length 61 mm, width 
15 mm. 
Body structures: mesothorax 5.4 mm long, metathorax 4.5 mm 
long. Abdomen about 40 mm long. Abdominal segments unequal, 
segments one and two shorter than the following ones. First tergite 
2.2 mm long, 19.6 mm wide; 5th tergite 5 mm long; 7th tergite 
1 1 mm wide. Claspers 9.2 mm long. 
The differences between the spinosa and lobata have been dis- 
cussed above. From S. laurentiauxi spec, nov., spinosa differs in the 
narrower wings, especially in their distal portions by the presence 
of the concavity along the posterior margin and by the more distal 
origin of Rs. 
Stenodictya laurentiauxi sp. nov. 
Figures 55, 56 
Stenodictya lobata Laurentiaux ( nec Brongniart), 1952: 233-247, pi. 10, 10a. 
The type specimen of this species has historical significance for 
the study of insect evolution. For many years the general belief 
of the students of fossil insects was that the paleopterous orders of 
the Paleozoic, being generally primitive in nature and geologically 
old, must have had chewing mouthparts. The erroneous nature of 
this concept was apparent when Laurentiaux (1952) described the 
presence of a long, haustellate beak in the “classical” representative 
