i6 STUDIES IN FOSSIL BOTANY 



Equisetaceous affinities. Though at one time some 

 botanists hesitated to accept this conclusion, we shall 

 find that it is now supported by irresistible evidence. 

 It is a matter of indifference whether, with Zeiller, we 

 name the whole group Equisetineae, after its sole living 

 representatives, or term it, with Endlicher, Calamarieae, 

 after its more important fossil members. The form 

 Equisetales will be adopted in this book, as indicating 

 a group of higher than ordinal rank. 



Many of the Calamarieae attained the dimensions of 

 trees. It is not possible to give the complete measure- 

 ments of any specimen, but the following facts may 

 afford some indication of the size attained. Mr. G. Wild 

 found in the roof of a coal-mine in Lancashire a medul- 

 lary cast of a Calamite 30 feet long ; the diameter of 

 the pith amounted to about 6 inches in the thickest part. 

 This cast must have represented a portion only of the 

 main trunk. In some of M. Grand'Eury's specimens 

 the cast of the pith is over a foot in diameter ; if the 

 whole tree were in proportion, it must have been of an 

 immense size. In other specimens of his, a height of 

 9 feet from the base scarcely takes us above the region 

 where the roots are given off. M. Grand'Eury 

 estimates the height of the stem in many of these 

 Calamarian trees at from 20 to 30 metres. 1 



As already mentioned, the most common mode of 

 preservation of Calamites is in the form of casts of the 

 medullary cavity (see Figs. 2 and 3). The marks 

 which they show correspond, not to any features of 

 the external surface, but to the print of the inner 



1 Flore carbonijere du Ddpartcment de la Loire, 1878, p. 29 ; Bassin 

 houiller du Gard, 1890, p. 210. 



