CHAPTEE X. 



I. EQUISETALES (continued). 

 (CALAMARIEAE.) 



In order to minimise repetition and digression the following 

 account of the Calamarieae is divided into sections, under each 

 of which a certain part of the subject is more particularly dealt 

 with. After a brief sketch of the history of our knowledge of 

 Calamites, and a short description of the characteristics of the 

 genus, the morphological features are more fully considered. 

 A description of the most striking features of the better known 

 Calamitean types is followed by a short discussion on the 

 question of nomenclature and classification, and reference is 

 made to the manner of occurrence of Calamites and to some 

 of the possible sources of error in identification. 



IV. Calamites. 



I. Historical Sketch. 



In the following account of the Calamarieae the generic 

 name Calamites is used in a somewhat compreheiisive sense. 

 As previous writers have pointed out, it is probable that under 

 this generic name there may be included more than one type of 

 plant worthy of generic designation. Owing to the various 

 opinions which have been held by different authors, as to the 

 relationship and botanical position of plants now generally 



