INTRODUCTION. 



The specimens described in a previous volume entitled The 

 Jurassic Flora, Part I., published in 1900' as one of the series of 

 Catalogues of the Mesozoic Plants in the Department of Geology 

 in the British Museum, were obtained from the rich plant-bearing 

 strata of the Yorkshire Coast. The present volume is devoted to 

 the description of English plants from Ehsetic, Liassic, and Oolitic 

 rocks. With the exception of the comparatively large assemblage 

 of forms afforded by the Stonesfield Slate of Oxfordshire, and the 

 smaller number of species obtained from the Liassic rocks of 

 Dorsetshire, the specimens described in the following pages repre- 

 sent scattered relics of various Jurassic floras, and are thus in 

 striking contrast to those which formed the subject of the earlier 

 volume. 



The few fragments of plants obtained from British Triassic 

 strata preserved in English Museums are too imperfect to be 

 determined with accuracy, and hopelessly inadequate to form the 

 subject of a separate memoir. In a monograph on the older 

 Mesozoic floras of the United States published in 1900, Professor 

 Lester "Ward ^ speaks of the incompleteness of the botanical records 

 of Triassic age in If orth American strata : our British records are 

 even more fragmentary and unsatisfactory. 



There are good reasons for believing that at the close of the 

 Permo-Carboniferous era the plant-world experienced a striking 

 change in its constitution.' It is, therefore, particularly unfor- 

 tunate that our records of Triassic floras are not more abundant. 



' Seward (00). See also Seward (00»). 

 2 Ward (00), p. 221. 

 ' Seward (02). 



