Seward: The Jurassic Flora of Yorkshire. 3 
follows, I have refrained from giving reference to the scattered 
literature on Mesozoic paleobotany. I may, however, refer 
to two volumes published by the Trustees of the British Museum, 
in which figures of British species will be found together with 
a general survey of the literature up to the year 1904.* In 
1903 I read a paper before the Geological Society of London, + 
in which an interesting addition to the British flora was des- 
cribed from material discovered by the Rev. John Hawell in 
a bed of ironstone near Marske-by-the-sea. Further additions 
to our knowledge of the Jurassic flora have since been made 
by Mr. Lane and Mr. Saunders as the result of their careful ex- 
amination of the Marske strata. In reference to the Marske 
species, Dictyozamites Hawelli, founded on the net-veined 
leaflets of a Cycadean frond, I may add that the geographical 
distribution of the genus Dictoyzamites, which in 1903 was 
represented by Jurassic species recorded from Japan, India, 
Bornholm, and Yorkshire, has recently been extended, so Dr. 
Nathorst tells me, to the Falkland Islands. 
ALG AND Funai. The few examples of Jurassic fossils 
identified as alge are not of sufficient botanical interest 
to be considered in a general sketch of the Yorkshire flora. 
It has been customary to refer to this class specimens which 
simulate some of the many forms assumed by recent seaweeds, 
but in the great majority of cases the algal nature of the fossils 
has not been demonstrated. Trustworthy examples of fungi 
are not likely to be discovered except in the petrified tissues 
of higher plants. 
Bryopuyta (Mosses and Liverworts). The single species 
referred to in this group is Marchantites erectus Leckenby, 
represented by sterile specimens only. Until better material 
is forthcoming it would be rash to speak with confidence as 
to the correctness of the determination, though the impressions 
described by Leckenby bear a striking resemblance to recent 
‘species of Marchantia and similar Liverworts. 
EQUISETALES. (Eguisetities columnaris Brongn, etc.), The 
genus Eguisetites is represented by casts of stems hardly 
distinguishable except in their larger diameter from those of 
existing Horsetails. More than one type is no doubt repre- 
sented, but this is a question of detail which need not be 
considered here. The interesting facts are that Equisetaceous 
plants grew in abundance in Jurassic soils, and that they ex- 
ceeded in size even the largest species which now exist in extra- 
* Seward, A. C., Catalogue of the Mesozoic Plants in the Depart- 
ment of Geology, British Museum. The Jurassic Flora: Pt. I. The 
Yorkshire Coast, 1900; Pt. II., Liassic and Oolitic floras of England 
(excluding the Inferior Oolite plants of the Yorkshire Coast), 1904. 
7; Seward, On the occurrence of Dictyozamites in England, ete. 
@uant- sour. Geol> Soc. Vols WIE. yp. 267,, 1903" 
Igtt Jan. 1. 
