38 Rey. A. E. Eaton’s Monograph 
Fossil Hphemeride. 
The oldest known fossil of this Family has been dis- 
covered in the Solenhofen slate. It is a fragment of a 
wing [Pl. I. fig. 10] and is in the British Museum. The 
best preserved of the extinct Ephemeride are those found 
in Stettin Amber. These species are such as would be 
likely to occur in a large river. They differ but slightly 
from extant species, and some of them are referable to 
recent Huropean genera. 
Many remains of insects from formations older than 
the Tertiary have been referred to the Hphemeride, but 
with doubtful accuracy. The following works contain 
notices of such fossils. 
1845. Brodie’s History of Fossil Insects, p. 127, pl. x. 4. [The actual 
specimen is in the British Museum; it exhibits an affinity to the Plani- 
pennia. | 
1856. F. Goldenburg, in Dunker & Meyer’s Paleontographica, iv. 
33-5, pl. ii. 5 & vi. 5, 6, described and figured three species of a genus 
Dictyoneura. 
[I consider this genus not to belong to the Ephemeride, because the 
subcosta ends abruptly at the nodus in the anterior wing; and because 
the thickened basal veinlet is absent. Dr. Dohrn ranks it with Eugereon.] 
1861. H.A. Hagen, in Meyer’s Paleontogr. x. 115-118, pl. xv. 2, 3, 5, 
described and figured Ephemera cellulosa, E. ? procera, and HE. mortua, 
together with E. prisca (Syn. Sciaria prisca, Germar, Noy. Act. Leopold. 
xix. 211-212, pl. xxiii. 11; Id., Giebel, Insect. d. Vorwelt, p. 230; Deutschl. 
Petrefakt, p. 640). [Cellulosa and procera have since been referred to 
Dictyoneura. It is impossible to determine the nature of the others, 
from the figures. ] 
1864. J.D. Dana, in Silliman’s American Journal of Science, xxxvii. 
34, described the genera Miamia and Hemeristia. 
[In 1866, Mr. 8S. H. Scudder erected a Family Paleopterina for these. 
Dr. Brauer, in 1866, cited them amongst the Ephemeride. Perhaps 
these genera are related to the Planipennia, as Mr. M’Lachlan suggests, 
or perhaps (but this is hardly probable) to Dictyoneura.} 
1868. Dr. A. Dohrn, in Meyer’s Paleontogr., gave a figure and de- 
scription of Hugereon Beckingii. [He referred it to the same group as 
Dictyoneura. Dr. Brauer, in the same year, ranked it amongst the 
Ephemeride. The condition of the mouth-organs clearly separates it 
from the Ephemeride; and the neuration of the wings favours Dr. Dohrn’s 
determination of its relationship. ] : 
1867. J. W. Dawson, in the Geological Magazine, iv. 385-388, pl. xvii. 
1-5, described and figured Haplophlebium Barnesii, Platephemera antiqua, 
Homothetus fossilis, and Xenoneura antiquorum. [They have all been 
regarded as allies of the Ephemeride. Haplophlebium, however, on 
account of the well-marked nodus in the fore-wing, and the character of 
the reticulation between the principal longitudinal nervures is, I think, 
related to Dictyoneura and Eugereon: Platephemera and Homothetus may 
possibly be of the Ephemeride, but there is nothing in the figures to make 
this certain: and there is no reason for considering that Xenoneura be- 
longs to this Family.] 
