366 
Psyche 
[ December 
Celonites rugiceps BischofF, 1928, Abhandl. Naturwiss. 
Ver. Bremen, XXVII, 1, p. 86, which was overlooked by 
me at the time, increases the number of species of Celonites 
of the Mediterranean Subregion to 10. 
In discussing the wing venation, I have overlooked one 
peculiarity of some importance, to which my attention has 
been called recently in a discussion with Prof. T. D. A. 
Cockerell. In all the genera of Masaridinae known to me, 
the marginal (or radial) cell (2d R1 + R2) of the fore 
wing is more or less truncate at the apex, its extremity 
being distinctly removed from the costal margin and gen- 
erally provided with an appendicular vein. As pointed 
out by Bradley (1922, Univ. of California Publ. Ent., I, 
No. 9, p. 376), the Masaridinae share this peculiarity with 
the Euparagiinae and Gayellinae, while a truncate or ap- 
pendiculate marginal cell is rather exceptional among the 
remainder of the Diploptera. I have seen it in certain 
species of Zethus , Lahus, Ancistrocerus , Odynerus, Ptero- 
ckilus, Monobia, and Montezumia, where it occurs rather 
sporadically, but it never seems to be present in the true 
social wasps of the subfamilies Ropalidiinse, Polistinae, Poly- 
biinae, Vespinae and Stenogastrinae. 
Although not of absolute value, the shape of the marginal 
cell may afford some help in tracing the affinities of the 
fossil insects that have been referred to the Diploptera. 
Since in fossil insects the venation of the wings is often 
much better preserved than the other parts, one is fully 
justified in using them to the utmost. The value of such 
work, however, depends entirely upon the reliability of 
venational characters among the living members of the 
particular group to which the fossil supposedly belongs. 
Fossils referred by various authors to the Diploptera 
have been found in Europe in the Tertiary of Chaumerac, 
France, in the Prussian amber (probably Lower Oligocene), 
in the Lower Oligocene of Aix in Provence, in the Oligocene 
of the Isle of Wight, England, in the Lower Miocene of 
Rodoboj in Croatia, in the Miocene of Parschlug in Steier- 
mark, and in the Upper Miocene of Oeningen in Baden. 
In North America all the specimens described thus far as 
Diploptera have been obtained in the (supposedly) Miocene 
