20 
Psyche 
[March 
Stenodictya thevenini differs from all other known species by its 
very long and narrow wing, pronounced concavity of the anterior 
margin and the presence of elongate cells in the archedictyon. 
Stenodictya pygmaea Meunier 
Figure 64 
Stenodictya pygmaea Meunier, 1911: 120, fig. 3; Meunier, 1912: 10, pi. 6, 
fig. 3; Handlirsch, 1919: 5, fig. 4. 
This species was based by Meunier on a specimen consisting of 
fragments of fore and hind wings and on a perfectly preserved pro- 
thoracic lobe. The structure of the lobe, which is unusually broad 
and exceptional in the branching of its veins, would seem to justify 
the recognition of this specimen as a separate species. 
The prothoracic lobe of the specimen of pygmaea, being unusually 
large and very well preserved, presents a rare opportunity to study 
this highly interesting structure of the Palaeodictyoptera in detail. 
Its narrow attachment, the shape of the lobe itself, the presence of 
veins and cross veins support Brongniart’s conclusion about the 
homology of this structure with the functional wings. The lobes 
are attached to the prothorax along a cuticular thickening in the 
middle part of the base, from which the veins radiate. Actually, 
the nature of the attachment corresponds to that of the functional 
wings. Since the veins lack any trace of concentration along the 
costal margin (“costalization”) , and since the base of the lobe shows 
no articular sclerites, the lobes probably never functioned as active 
organs of flight. 
The venational pattern of prothoracic lobes does not completely 
follow Lameere’s (1922) hypothetical scheme of the original vena- 
tion of true wings, the veins (R, Rs, MA, MP) always arising from 
the ridge separately, not from two common stems. This is true of 
all prothoracic lobes which I have been able to study. Nevertheless, 
the “cubitus” in almost all of the prothoracic lobes is very much 
like that of the functional wings, being characteristically S-shaped 
and two-branched. The number of branches arising from the cutic- 
ular ridge is variable and differs to some extent in each specimen. 
This is because in most specimens the twigs of “Sc” arise from the 
base separately and also because the number of independent “anal” 
veins varies. There is no homologizing of the veins by convexities 
and concavities, since, in all of the lobes which I have had the 
opportunity to study, the fluting is absent. 
The independent origin of the branches of veins in the prothoracic 
lobes (excepting Cu and sometimes Sc) seems to me to be a derived 
