CHAPTER III 



EQUISETALES FRUCTIFICATIONS AND 



CLASSIFICATION 



Calamostachys ; Palaeostachya ; Cingularia ; Archaeo- 

 calamites ; Macrostachya ; Classification of Cala- 

 marieae ; Mesozoic Equisetales. 



i. The Fructifications. — We have now to consider 

 the important subject of the fructifications of the 

 Calamarieae. There are four main types of cone 

 referred to this group, and known to us in some detail,, 

 though no doubt there are many more not so thoroughly 

 investigated. First we will take the type of Cala- 

 mostachys, representatives of which, with structure pre- 

 served, are common in the English Coal-measures. 

 This genus is characterised by the fact that the cone 

 does not merely bear whorls of peltate sporangiferous 

 scales, as in Equisetum, but that the successive fertile 

 whorls are separated from one another by intermediate 

 and equidistant verticils of sterile bracts (see Figs. 17 

 and 21). The peltate scales by themselves look like 

 those of an Equisetaceous fructification (see Figs. 18 

 and 20). It is better to use the word sporangiophore 

 in this connection, rather than sporophyll, for, as we 



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