4 82 
Psyche 
[December 
times, with widely separated branches; CuP with only one, wide 
fork. Branches of main veins near posterior margin S-shaped. Anal 
area with about 7 relatively densely arranged branches, some of 
them with short forks. Cross veins in sc-r area dense but simple, 
not connected by anastomoses. 
Megaptilus blanchardi recalls Dictyoptilus sepultus (Eugere- 
onidae) by its posteriorly curved veins with S-shaped tips along the 
posterior margin, by the fore wing broadening at the end of CuA 
and by the wide fork of MP. Also, the cross venation, though 
denser, is not very different from that of sepultus , either. The hind 
wing of Lithoptilus boulei (Meunier, 1908) shows the same S-shaped 
tips of M and Cu branches along the posterior margin as the fore 
wing of blanchardi. 
Genus Lithoptilus Lameere 
Lithoptilus Lameere, 1917: 157; Demoulin, 1958: 3. 
Anaxion Handlirsch, 1919: 19. 
Type species: Lithoptilus boulei (Meunier, 1908) (OD) 
This genus was erected by Lameere (1917, p. 157) for Archae- 
optilus boulei Meunier, 1908. Lameere noted that this genus seemed 
closely related to Homoioptera , differing only in the shorter and 
broader wings but he could not determine to which pair of wings 
the type specimen belonged. Handlirsch, noting the broad subcostal 
area, assumed the type specimen to be a fore wing and, having 
overlooked Lameere’s paper, erected a new genus for boulei , Anaxion 
( Anaxionidae) , which he associated with the Breyeriidae. Finally, 
Demoulin (1958) without seeing any of the specimens, concluded 
that Lithoptilus was based on a hind wing, vestigial as in most 
recent Ephemeroptera. As the closest related genus he suggested 
Rhabdoptilus and referred both genera to the Rhabdoptilidae Hand- 
lirsch. Demoulin’s statement about the vestigial hind wing character 
of the type specimen of Lithoptilus is correct but there is no indica- 
tion of relationship to Rhabdoptilus. 
The systematic position of Lithoptilus becomes much clearer after 
the shortened hind wings of Eugereonidae and Megaptilidae are 
studied. Although Lithoptilus recalls some Eugereonidae by the shape 
of the hind wing (e.g., Peromaptera ) , the venational pattern and 
cross veins are most like those of Megaptilus. The range of varia- 
tion of the hind wing shape seems to have been wide in the Eugere- 
onidae and it probabaly was also in the Megaptilidae. 
The following account is based upon the hind wing of Lithoptilus 
boulei (Meunier). 
