No. 415.] REVIEWS OF RECENT LITERATURE. 609 
The Jurassic in Great Britain, as in North America, was essen- 
tially the Age of the Cycads, a fact strongly emphasized by the 
Yorkshire flora where Williamsonia, Otozomites, and Nilssonia 
formed conspicuous elements. 
As already pointed out, the Conifer are much less abundant in 
this flora than either the ferns or the cycads, but the evidence so 
far obtained makes it impossible to determine how far this is to be 
accepted as an expression of their actual relation to the original 
flora, since local conditions may have operated to exclude a large 
proportion of such plants from preservation as fossils. The nearest 
existing types appear to be represented chiefly by various species of 
Araucaria, although Podocarpus is also suggested by /Vagetopsis 
anglica. The Abietinee, which assume an important position in 
the Wealden and Lower Cretaceous floras, have no well-defined 
representatives in the Yorkshire flora. 
So far as any general conclusions are justifiable upon the basis 
of the present studies, it would seem probable that in seeking com- 
parisons between the Jurassic flora of the Yorkshire coast and the 
vegetation of the present time, we must turn to the southern tropics. 
In the general character of the vegetation, therefore, as also in the 
luxuriant growth of Equisetums and ferns, we observe evidence not 
only of a moist climate, but also indications that the climate of 
England during Jurassic time must have been considerably more 
tropical than at present. D. P. PENHALLOW 
