276 BULLETIN OF THE 
question here treated — the evolution of this class of insects — is pos- 
sible. The facts to be registered for such an advance must be unques- 
tionable facts, and that is not the case with those stated in this 
publication. 
* As the simpler Devonian Insects have certain special relations with 
the Ephemeridæ, their description is preceded by an account of the wing 
structure of the modern Mayflies, as a basis of comparison." (p. 4.) 
The simple fact that none of the fossils has any relation whatsoever 
to the Ephemeridæ, is a sufficient, objection to the descriptions and con- 
clusions relating to this family. Some exceptions made by the author 
in the account of the wing-structure of Lachlania and Oligoneuria prove 
erroneous after a careful examination of the insects. The mediastinal 
vein is present in Lachlania and Oligoneuria, and the scapular vein ter- 
minates at the tip in Lachlania. "The intercalary vein of Coloburus is 
to be found also in Ephemerella gibba and in Heptagenia Bellieri, 
Platephemera antiqua. 
The specimen is in excellent condition; I have before me the type, Fig. 9. 
This species has nothing whatsoever to do with the Ephemeridæ, and I remark 
here that my deliberate determination is not based upon a difference of opinion, 
but merely on the simple evidence of facts. The specimen is a part of the 
apical half, without the tip, of a wing of a gigantic dragonfly. Fig. 10 shows 
on the hind margin the end of the sector medius, where the margin is often 
a little retracted. Nearer the tip (in Figs.9 and 10) the sector nodalis and 
sub-nodalis run one near the other, as commonly in dragonflies. No ptero- 
stigma is visible; but we find it wanting or sometimes slightly indicated in 
other fossil species. The statement of the author, that “ the marginal vein 
runs close to, but does not form, the margin,” confirms my determination, 
as just in Odonata this structure is very common, but not in Ephemeride. 
The conclusion of the author that a general similarity of structure of P. antiqua 
“with Dictyoneura may be conceded,” will not be shared on comparing the 
figures of the species published by Goldenberg. The existing part of the wing 
compared with the known fossil species from Solenhofen cannot be larger than 
about one third of the whole length of the wing. To judge from the termi- 
nation of the sector nodalis, something less than 20 mm. of the tip are want- 
ing, much more than is indicated by the outline of the figure. To judge from 
the distance and the direction of the mediana and the sector nodalis to the base, 
about 20 mm. must be wanting to the nodus. It would be the largest known 
species, the length of the wing about 100mm. There is no character in the 
fragment for a closer determination except the suddenly narrowed second cubi- 
tal space ; and this is not mentioned by the author. We find a similar arrange- 
ment in Stenophlebia. 
