304 ROYAL SOCIETY OF CANADA 
Upon comparison with the European forms recorded by Brongniart 
(4), a very striking resemblance is observed to exist between our pre- 
sent specimens and P. arborescens. This latter is characterized by 
having “ Pinne, ? cm. long and 6 mm. broad at the base, at first linear 
but then gradually and uniformly tapering toward the apex from above 
the middle; pinnules, 3 mm.x1.5 mm.” While a careful comparison 
of the two specimens shows a remarkable resemblance, it is to be noted 
that the one now under special consideration is much the larger, a 
feature which constitutes the chief and most essential difference. Fur- 
thermore, P. arborescens is a Carboniferous type from St. Etienne, and 
I am not aware that it has been definitely observed in any later forma- 
tion. While, therefore, it is not altogether possible to establish specific 
identity between the two, there is little reason to doubt that G. gilbert- 
thompsoni is the modern representative of P. arborescens. 
Directing comparisons to Tertiary forms, it is found that the genus 
is but sparingly represented in that age. Pecopteris torellii of Heer, 
is an element of the Eocene flora of Unga Island (42), while it is also 
common to the Miocene of the Island of Saghalien (21), but as this 
plant can no longer be regarded as one of the Gleicheniaceæ, but rather, 
as Lesquereux points out, a true Osmunda, it must be excluded from 
further discussion in this connection. 
Perhaps the nearest representative of this type is to be found in 
Gleichenia zippei, Heer, from the Kome beds of Greenland (35:. p. 44, 
pl. iv, v, vi, vil). While there is a general resemblance which unques- 
tionably brings the two into generic relation, there are important differ- 
ences in the length and shape of the pinnules which definitely establish 
a specific difference. 
We are thus brought to a comparison with the geologically most 
recent of all known species — P. sepulta, Newb. This plant was 
described by Newberry in 1882 (45) as having been obtained from the 
Eocene of Green River, Wyoming. No figure is given, but the descrip- 
tion shows the pinnules to be confluent, united by one-third of their 
length, slightly curved upward and flabellate on the upper side. 
It is thus clear that P. sepulta is not even remotely related 
to the one under discussion, and from the evidence collected, the latter 
must be regarded as altogether a new one, for which a definite name 
is demanded. But since the above was written, a copy of Ward’s latest 
contribution to our knowledge of the Mesozoic flora has come to hand 
(57: 616), and in this way my attention was at oncedrawn to a 
description and figures of Gleichenia gilbert-thompsoni, as originally 
described by Fontaine, as being at least closely similar to the Skagit 
