THE CRETACEOUS FLORA. 
55 
With regard to the conditions of deposition, Professor Les- 
quereux remarks, that the character of the leaves found in the 
Dakota group, and their analogy with species of our time, seem 
at first to refer them to a dry land flora ; this is, however, not 
positively the case. The most abundant representative of the 
Cretaceous flora, the Sassafras, is remarkably similar to the 
present Sassafras officinalis , which inhabits every kind of 
ground and station, from the dry hills of Ohio to the low swamps 
of Arkansas. The numerous leaves of Laurus are comparable 
to those of L. Carolinian a , a shore plant ; as are also the Pla- 
tanus , Magnolia , Pop ulus , Salix , Menispermites; the essential 
types of the Dakota group being, therefore, those of low islands 
or low shores, rather than hills or dry land. Professor Mudge 
says the characteristic of the local deposits of this group in the 
State of Kansas indicate that the forests were on small islands 
scattered over the Cretaceous ocean.* 
In Cumberland and Nelson provinces, New Zealand, rocks 
referable to the Cretaceous age by their fossils overlie valuable 
coal-seams, locally altered into anthracite, and associated with 
the shales and sandstones is a rich dicotyledonous flora, both 
angiosperms and gymnosperms, as the Myrtacege, Fagus, 
Coprosma, Dammara, Phyllocladus, Podocarpus, Dacrydium, &cv, 
many of the genera still existing in the New Zealand flora. 
There is one locality at Pakawu, where the genera Pecopteris 
and Taeniopteris are clearly associated with the dicotyledonous 
plants, the species however being different from those represent- 
ing the same genera in an underlying sandstone, which is 
undoubtedly of Jurassic age, and which species are mostly iden- 
tical with those found in the Rahmajal series of India. 
Overlying the coal-bearing rocks are a series of conglomerates, 
sandstones, calcareous marls and chalk, with flints in some 
localities more or less developed, and there is evidence in the 
upper part of this series of fossils with an Eocene facies, succeeded 
by lignite beds indicating a land surface.f 
The Cretaceous period may be divided into two distinct 
periods according to the nature of its terrestrial vegetation, and 
these somewhat agree with the ordinary geological divisions ; 
including the Wealden, Neocomian, and Gault in the lower; 
and upper green sand, lower, middle, and upper chalk in the 
upper division. 
M. Schimper has divided the Cretaceous flora as follows : — 
Etage Inferieur (Neocomien, Urgonien), Etage Moyen et 
Superieur (Aptien to Danien), 
The general Cretaceous flora includes : Thallogens, as Algse ; 
Acrogens, as ferns and equisetum ; Gymnogens, as conifers 
* “ Trans. Kansas State Board of Agriculture,” p. 95. 
t Dr. Hector, “ Trans. New Zealand Institute,” vols. ii. and vi. 
