xx FLORA OF TASMANIA. 
its genera are the same. The prevalent types are Gymnospermous Dicotyledons, especially Cycadece, 
and a great abundance of Tree-ferns. 
The New Red Sandstone, or Trias group, presents plants more analogous to those of the Oolite 
than to those of the Carboniferous epoch, but they have also much in common with the latter. 
Voltzia, a remarkable genus of Conifers, appears to be peculiar to this period. 
In the Lias numerous species of Cycadea have been found, with various Conifers and many 
Ferns. No other Dicotyledonous or any Monocotyledonous plants have as yet been discovered, but 
it is difficult to believe that none such should have existed at a period when wood-boring and herb- 
devouring insects, belonging to modern genera, were extremely abundant, as has been proved by the 
researches of Mr. Brodie and Mr. Westwood* 
The Oolite contains numerous Cycadea, Conifer®, and Ferns, and more herbivorous genera of 
insects ; and here Monocotyledonous vegetables are recognizable in Podocarya and other Pandaneous 
plants. A cone of Pinus has been discovered in the Purbeck, and one of Araucaria in the inferior 
Oolite of Somersetshire. 
In the Cretaceous group, Dicotyledons of a very high type appear. A good many species are enu- 
meratedt by Dr. Debey, of Aix-la-Chapelle, including a species of Juglans, a genus belonging to an 
Order of highly-developed floral structure and complex affinities. J 
Characea appear for the first time at this epoch, and are apparently wholly similar in structure 
to those of the present day. 
The Tertiary strata present large assemblages of plants of so many existing Genera and Orders, 
that it can hardly be doubted but that even the earliest Flora of that "period was almost as complex 
and varied as that of our own. In the lowest Eocene beds are found Anonacece, Nipa, Acacia, and 
Cucurbitacea>.% In the Bagshot sands some silicified wood has been found, which may confidently 
be referred to BanJcsia, and which is, in fact, scarcely distinguishable from recent and fossil Aus- 
tralian Banksia wood.|| 
* These insects include species of the existing common European geneva, Mater, Gryllus, Hemerobius, Ephe- 
I ida, Panorpa, and Carahus. Of all conspicuous tribes of plants the Cycadea, FUices Conifera and 
Lycopodiace* perhaps support the fewest insects, and the association of the above-named insects with a * 
consisting solely or mainly of plants of these Orders is quite inconceivable. 
f Quart, Journ. Geol. Soc. vii. pt. 1. misc. p. 110. 
% Professor Oswald Heer, of Zurich, in an interesting little paper (Quelques Mots sur les Novers), in Bibl 
Univ. Uener. bep lboS, argues from the fact of the early appearance o{ Juglans in the geological series, that this 
genus must be a low type of the Dicotyledonous class to which it belongs. The position of Jugla . i, , „.,,,; d ' D 
the pivh ,,t .tat, n! „, v clarification of Dicotyledonous Orders, as it has equal claims to be rank, 
winch are very high m tire series, and with Cupnliferx, which are placed very low; and were the grounds for our 
on characters of ascertained relative value, such an argument might be admis- 
sible; but the system which sunders these Orders is a purely artificial one, and Juglans with its allies would prove 
t so if o her proofs were wanting; for it absolutely combines TerebhUhace* and Cupuliferre into one natura 
m which (as in so many others) there u a gradual passage from great complexity of floral organ- 
str 21 2 " C ?" titoti « of these and the otl - genera which I have enamel d 
^:-t: -tr as evidence of as ui * d — - — **• 
-lu^^ 
ery respect to the opalized B; 
though it is so perfectly rfmSl.. ~ ^ ^^ been *W 
uggest t 
... „»„«. u U u Ul5 as iu us xmgnsn origin, 
