THE 
tjll^- 
JOURNAL 
OP 
BOTANY, 
BRITISH AND FOREIGN. 
\ 
ON GYMNOSPERMATOUS FRUITS FROM THE SECON- 
DARY ROCKS OF BRITAIN. 
By William Carruthers, F.L.S., 
, BOTANICAL DEPARTMENT, BRITISH MUSEUM. 
(Plates LVII.-LX.) 
gymnosper 
in Secondary strata, viz. 
Con ift 
been observed, as for as I know, of any plant belonging to the 
Gnetacea. 
Con [ft 
from the period of the Old Red Sandstone ; but it is very doubtful 
whether the Palreozoic fruits and leaves which have been referred to 
Cycadetz have anything whatever to do with that Order. 
Fossil wood, leaves, and frnits, afford the means of determining the 
existence of vegetables during any geological period. 
The trunks and foliage of Cycadece are so remarkable that fossil 
fragments of them can, as a rule, be determined with certainty. The 
trunks are generally short, and composed externally of the bases of 
the leaves, while internally they consist of a large medulla, either 
simple or traversed by numerous vascular bundles, and surrounded 
by one or more woody cylinders. The trunks from Purbeck, which 
Cycadoidea 
those from the Wealden, named 
Clathraria by Mantell, have all the characters of Cycadean sterns. 
The leaves are remarkably uniform in the modern representatives of 
[ 
u 
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* 
■ ■■-■"-.■■;■. ;. 
