PLATE 50. 
PHYTOLITHUS imhi'icatus, heretofore described. See P. 14. 
I received this specimen from Lancashire *. It is Intro- 
duced here to show the form and disposition of the scales in 
larger examples of the fossil, than those before represented, 
not having met with any of the same size as perfect in this 
county. 
The ends of the specimen are broken ; and it is destitute 
of leaves, but there are vestiges of them in some small por- 
tions of the matrix, which still adhere to the scales. It 
consists of a hard, close, light-coloured grit — The surface 
varnished with a thin, black, bituminous or coaly matter. 
* From Mr. John Collins, of Wigan, who has collected with con- 
siderable diligence the petrifactions of that neighbourhood. 
