THE SPHENOPHYLLS 



241 



size of an average modern species, lie will be able to 



form some sort of a mental picture of the peculiar cast 



which the Calamites would 



give to the Palaeozoic land- 



scape. Since the halcyon 



days of the Calamites, which 



were in greatest abundance in 



the Carboniferous Period, the 



Equisetales as a group have 



gradually dwindled in size 



and importance, and we know 



from the few existing species 



how extensive the falling off 



has been. The group has 



displayed a tenacity which 



commands our respect, and 



one cannot avoid admiration 



for a race which has sur- 



vived the chances and vaga- 



ries of many aeons, and whose 



existing forms are the repre- 



sentatives of an aristocratic 



ancestry. 



- ARCH^OCALAMITES RA- 

 DIATUS . BRANCH WITH LEAVES 

 IN WHORLS ; LEAVES WITH RE- 



A glance at the SPHENO- 



PHYLLALES will terminate our 



j.i i r -n i 



review Ot the chief Palaeozoic 



plant groups. In the absence 



of the researches of palseo- 



botanists, we should cer- 



tainly have had no knowledge of the Sphenophylls. 



They seem to have arisen and become extinct in the 



31 





