212 
Psyche 
[June 
in effect designated specimen 37-8 as the lectotype of dohrni by 
placing the additional specimens in other species, as follows: 37-11 
and 37-12 were placed in a distinct genus Mecynostomites brong- 
niarti; 37-9 to a new genus and species Paramecynostoma dohrnianum ; 
and specimen 37-10 to another new genus and species, Pseudo- 
mecynostoma dubium. All of these four specimens consist of wing 
fragments, poorly preserved and are not sufficient to permit family 
classification. These genera are here placed in the Palaeodictyoptera 
incerta,e familiae. The following account is based upon the lectotype 
specimen of dohrni (37-8). 
Wings dark in color. Fore wings: anterior margin convex, sub- 
costal area very broad in the basal half; Sc, R, Rs very close to 
each other; R and Rs bent in the apical part so as to be parallel 
with the anterior margin; first branch of Rs arising soon after its 
origin; MA weakly branched, MP with several branches; CuA 
forked several times, CuP sending off a few branches. Cross veins 
in the subcostal area long ? bent and regular. In the hind wing the 
subcostal area is narrow, and Rs and M are not markedly curved 
towards the posterior margin. 
The short condition of Sc apparently developed independently 
in several families of the Palaeodictyoptera, such as the Breyeriidae, 
Calvertiellidae, etc., probably in conjunction with the development 
of short and broad wings with numerous cross veins. It does not 
apparently indicate phylogenetic relationship. 
Mecynostomata dohrni (Brongniart) 
Figure 28 
Mecynostoma dohrni Brongniart, 1893: 452, pi. 37, fig. 8; Handlirsch, 
1906: 120, pi. 13, fig. 1; Lameere, 1917: 102; Lameere, 1917: 184; 
Handlirsch, 1919: 24, figs. 26-27; Laurentiaux, 1953: 415. 
Mecynostomata dohrni , Metcalf, 1952: 230. 
The lectotype specimen, 37-8, shows three faintly preserved wings, 
a very well preserved head, showing the clypeus, labrum and beak, 
with faint indications of palpi, and with almost a complete fore leg. 
The clypeus is rather small in comparison with that of other 
Palaeodictyoptera. The labrum is elongate, lanceolate in form, a 
type which was quite common in the Palaeodictyoptera. The terminal 
parts of the inner stylets of the beak are very thin, pointed, and 
straight, while the outer pair is much broader, obtuse at the ends 
and probably flexible to some extent. The fore leg shows five well 
preserved tarsal segments, the first the longest; the claws are robust 
and the arolium is circular. For some reason, both Handlirsch and 
