* 
. es 
Pierre KAIST 
FOR 1911. 
THE JURASSIC FLORA OF YORKSHIRE. * 
A. C. SEWARD, M.A., F.R.S., ec. 
From the point of view of their fossil contents, the estuarine 
beds of East Yorkshire are among the most famous and im- 
portant strata in the world. Since the publication in 1822 of 
‘A Geological Survey of the Yorkshire Coast,’ by Young and 
Bird, much attention has been paid to the Jurassic plants of 
Yorkshire by British and Foreign students of ancient floras. 
During the first half of the nineteenth century a considerable 
amount of work was done by such pioneers as William Bean, 
his nephew John Williamson, his great-nephew William Craw- 
ford Williamson, by John Phillips and others. The ‘ Illustra- 
_ tions of the Geology of Yorkshire,’ is dedicated by ‘ an affec- 
tionate nephew and grateful pupil’ to William Smith, who was 
spoken of by Professor Adam Sedgwick (when Mr. Smith 
received from him as President of the Geological Society of 
London the first Wollaston medal) as ‘ the first in this country 
to discover and to teach the identification of strata, and to 
determine their succession by means of the imbedded fossils.’ 
Professor Williamson, in his fascinating Reminiscences of a 
Yorkshire naturalist, tells us how ‘in 1826 Dr. Smith and his 
eccentric wife,’ established themselves in his father’s house at 
Scarborough, “where they dwelt for a considerable time.’ 
The association of William Smith with Scarborough connects 
the plant-beds of the Yorkshire coast with the dawn of strati- 
graphical geology. 
It is not my intention to deal with the history of our know- 
ledge of the plant records of British Jurassic rocks, but rather 
to give a general sketch of the flora which the labours of en- 
thusiastic Yorkshire naturalists have enabled us to investigate. 
Before attempting this, I should like to emphasise as strongly 
as I can the importance of doing our utmost to take advantage 
of the exceptional opportunities afforded by the geological 
structure of the Yorkshire cliffs for obtaining a fuller knowledge 
of the vegetation which flourished in western Europe during 
the Jurassic era. The notes by Messrs. G. F. Lane and T. 
Saunders} recently published in ‘ The Naturalist,’ illustrate 
the importance of searching for records in exposures of Oolitic 
Strata in inland as well as in coastal localities. 
* The Presidential Address to the Yorkshire Naturalists’ Union, 
delivered at Middlesborough, December 17th, rg1o. 
+ ‘The Naturalist,’ March, 1909, and January, 1910. 
Igit Jan. I 
