130 
Psyche 
June- August 
Odanta, and a low nervure, the posterior median; this last 
the Odonata, and a low nervure, the posterior median; this 
last is missing in the Odonata, which have retained only the 
upper anterior median. 
From the base of the wing of Meganeura, a little behind 
the radio-median trunk arises a long, winding, simple nerve 
(Brongniart’s VIII) which is very low; comparison with Dic- 
tyoptilus shows that it must be the posterior cubital (Scu), as 
the anterior upper cubital which approaches very near to the 
posterior median in Dictyoptilus is evidently absent. It is 
certain that this nervure Scu is represented in the Odonata by 
the low nervure at present known as Cu^ 
Still a third nervure leaves the base of the wing of Mega- 
neura; it is parallel to the posterior cubital and is high (Bron- 
gniart’s IX); almost on the level at which the radial detaches 
itself from its sector and from the median, this high nervure 
gives rise to a low nervure (Brongniart’s X) ; we now have the 
first and second anal, the penultimate nervure with its sector, 
and this nervure corresponds to Cu- of the Odonata. 
We know that in the Odonata a trachea gives rise to Cu^ 
and Cu2, these nervures proceeding from a common trunk, and 
another trachea furnishes the nervure designated as lA; this 
last attaches itself very near the base of the wing to the common 
trunk of Cu^ and Cu^, and then becomes independent. 
We have the same thing with Meganeura and even probably 
with Dictyoptilus; no attention has been paid to it, because Ch, 
Brongniart has neither seen nor figured anything, except in 
Meganeura; between the base of the wing and the level of the 
division of the penultimate into P and Sp, there exists an obli- 
que nervure which attaches the cubital again to the last nervure 
arising from the base of the wing. ^It is evidently a case of an 
anastomosis between the cubital and the penultimate, the latter 
proceeding thus from the cubital, as in the Odonata. So the 
last nervure which leaves the base of the wing in Meganeura is 
iThis oblique nervure is immediately recognizable in the photographic reproduction of a 
wing-fragment of Meganeura, given by Bolton (Quart. Journ. Geol. Soc., vol. 70 (1914), pi. 
18, fig. 1) and in that of another Meganeura published by Boule (Ann. de Paleont, vol. 4 (1909) 
pi. 17, fig. 2); E. H. Sellards has figured it in Typus permianus (American Journ. Sci., vol. 23 
(1907), p. 250, fig. 1, p. 252, fig. 2. 
