TIIE CRETACEOUS FLORA. 
51 
predominant. Besides extinct genera there are others, con- 
sidered to belong* to living forms, as Adenanthus, Banksia, 
Pryandra, Grevillea, Hakea, and Persoonia. Associated with 
these Proteaceae are the tig, bog-myrtle, willow, poplar, the 
oak, beech and dryophyllum, a cupuiiferous genus allied to the 
chestnut-oak, also Credneria, and cissites related to the Arnpe- 
lidece, together with some forms of the Myrtaceae, as Eu- 
calyptus, &c.* 
The eastern continent, like the western, affords equally inter- 
esting facts as regards the old land surfaces of the Cretaceous 
period. In Spitzbergen and Greenland, under latitude 70° N. — 
where now almost perpetual ice and snow reign, with the dis- 
appearance of the snow there suddenly springs forth a herbaceous 
vegetation, rushing into leaf and flower, to be speedily de- 
stroyed by the return of the winter’s frost after a very short 
summer — there is evidence of a forest vegetation at the Cre- 
taceous and Miocene periods, indicative of a temperate or even 
subtropical climate, thus showing that great physical and 
cosmical changes have taken place in the Arctic regions, and 
infeiring at those periods a different distribution of land and 
of warm oceanic currents from that which obtains at present. 
The researches of Professor Nordenskiold, in connection with 
the late Swedish expeditions, and the subsequent determinations 
of Professor Heer, have thrown considerable light on the ancient 
floras and climates of the Arctic regions. f The Cretaceous strata 
of Greenland, according to Professor Heer, belong to two dif- 
ferent stages, and contain different floras. The lowest division 
is met with at Kome or Kook, and other places on the north 
side of the Noursoak Peninsula in North-western Greenland. 
These strata, considered to be of middle Neocomian age (Ur- 
gonian), contain some plants which resemble those of Wernsdorf 
in the Carpathians. About seventy-five species are described, 
belonging to fifteen families ; more than one-half are Cryp- 
togams, chiefly of the fern tribe, among which the species of 
Gleichenia play the chief part, a genus which still flourishes in 
the vicinity of the tropics and warmer portions of the temperate 
zone ; but Sphenopteris and Pecoptens are not rare. The 
other plants are chiefly gymnosperms — the Conifers© — some of 
which are nearly related to forms still existing in Florida, Jap»an, 
* Debey, H. M. Uebersicht der urweltliclien Pflnnzen des Kreidege- 
birges, iiberhaupt und der Aachener Kreideschicbteu m.'besondere.” — Kin ini. 
u. Westphal. Yerhand. 1848, pp. 113-142. 
Debev, II. M. und Ettingshausen. “ Die urweltliclien ThaTophyten d^s 
Kreidegebirges von Aachen und Maestricht.” — Wien. Denkschr. Akad. 
Wiss, xvi. 1859, pp. 131-214. “ Die urweltlichen Acrobryen." — Ibid. xvii. 
1859, pp. 183-248. 
t “Flora fossilis Arctica.’’ — Zurich, 1868, 1875. 
