1923] 
The Wing-Venation of Insects 
129 
the nervure lA of current usage, high, is the third anal or 
ultimate ([/), partly attached to the penultimate. 
The neuration of the wing of the Libellulidse would not be 
exactly similar to that of the Ephemeroidea, contrary to what 
has been considered heretofore, and the comparison which has 
been made with that of Ectoblastic insects is rather lame. 
The evolution of fossil Odonatoptera, which I have been 
able to study at the Paris Museum, will show us this. • 
In the Dictyoneuridae of the coal measures the primitive 
neuration is complete and typical, but very often the anterior 
median and anterior cubital are simple (as in the genus Steno- 
dictya Ch. Brongn.) 
Dictyoptilus Ch. Brongn., of the Stephanien, has a more 
elongated wing; the median is contiguous to the radial at the 
base of the wing, which gives a small pre-costal space, — all 
characters which are accentuated in the Protodonata^ 
These last have the median confused with the radial at 
the base of the wing, and the radial sector arises from the median, 
as in the Ephemeroidea. 
Let us now consider Meganeura Monyi of Ch. Brongniart, 
the giant Libellulid of Commentry, and compare its neuration, 
on one hand with that of Dictoptilus, on the other hand with 
that of the Odonata, the nervures being for the latter designated 
according to their current names. ^ 
In Meganeura, we see, leaving the common trunk which 
leads to the radial, a nervure which soon divides into a lower 
anterior and an upper posterior nervure; the first (BrongniarCsV) 
corresponds evidently to the radial sector in Dictyoptilus, and 
it divides, as in the latter; into two low nervures Brongniart’s 
IV and V) in which we recognize, on one hand, M^ ^ ]y[g. on the 
other, M3, of the Odonata; the second (Brongniart’s VII) is 
the median in Dictyoptilus, which is reunited to the radial at 
the base of the latter’s sector; this median is divided into a high 
nervure, the anterior median, in which we recognize M^ of the 
iSee the fine photographic reproductions of the wing of Dictyoptilus {Cockerelliella) 
sepultus F. Meun, published by Boule in the Annales de Paleontologie, vo. 7, pi. 7, figs. 4, 4a. 
2The figure of the wings of Meganeura monyi in the work of Brongniart (PI. 42) is correct; in 
Handlirsch the fore wing is in part inaccurate. 
