FLOKA OF THE UPPER CHALK, 
303 
as amounting to more than two hundred, of which sixty-sev¬ 
en are cryptogamous, chiefly ferns, twenty species of which 
can be well determined, most of them being in fructification. 
The scars on the bark of one or two are supposed to indicate 
tree-ferns. Of thirteen genera three are still existing, name¬ 
ly, Gleichenia^ now inhabiting the Cape of Good Hope and 
'New Holland; Lygodium^j\ow spread extensively through 
tropical regions, but having some species which live in Ja¬ 
pan and North America; and Asplenium^ a cosmopolite 
form. Among the phsenogamous plants, the Conifers are 
abundant, the most common belonging to a genus called 
Cycadopteris by Debey, and hardly separable from Sequoia 
(or Wellingtonia), of which both the cones and branches are 
preserved. When I visited Aix, I found the silicified wood 
of this plant very plentifully dispersed through the white 
sands in the pits near that city. In one silicified trunk 200 
rings of annual growth could be counted. Species of Arau¬ 
caria like those of Australia are also‘found. Cycads are ex¬ 
tremely rare, and of Monocotyledons there are but few. No 
palms have been recognized with certainty, but the genus 
Pandanus, or screw pine, has been distinctly made out. 
The number of the Dicotyledonous Angiosperms is the most 
striking feature in so ancient a flora.* 
Among them we find the familiar forms of the Oak, Fig, 
and Walnut {Quercus^ Fims^ and Juglans)^ of the last both 
the nuts and leaves; also several genera of the Myrtacese. 
But the predominant order is the Proteaceae, of which there 
are between sixty and seventy supposed species, many of 
extinct genera, but some referred to the following living 
forms—Dryandra, Grevillea, Hakea, Banksia, Persoonia—all 
* In this and subsequent remarks on fossil plants I shall often use Dr. 
Lindley’s terms, as most familiar in this country; but as tliose of M. A. 
Brongniart are much cited, it may be useful to geologists to give a table 
explaining the corresponding names of groups so much spoken of in 
Lichens, sea-weeds, fungi. 
Mosses, equisetums, ferns, lyco¬ 
podiums—Lepidodendra. 
Conifers and Cycads. 
Compositse, leguminosse, umbel- 
liferoe, cruciferae, heaths, etc. 
All native European trees ex¬ 
cept conifers. 
Palms, lilies, aloes, rushes, grass¬ 
es, etc. 
a 
a 
fcfi 
c J 
£_■ % 
Brongniart. Liudley. 
Cryptogamous am-I 
phigens, or cellu- ^ Thallogens. 
lar cryptogamic. ) 
Cryptogamous aero- Acrogens. 
gens. 
Dicotyledonous gym- Gymnogens. 
nosperms. 
4. Dicot. angiosperms. 
5. Monocotyledons. 
Exogens. 
Endogens. 
