THE ERA OF THE FERNS 
Between the great shafts of the lycopods of the Penn¬ 
sylvanian forest, another plant type was visible, the 
cordaitales. They were a plant somewhat related to the 
modern conifers, but they did not belong to exactly the 
same class. These large trees bore enormous needles, 
sometimes three feet long and from one-half to four 
inches wide. 
There was also an abundance of tree-like horsetails 
(equisetales), of which the principal genus is called 
Calamites, which is a generic name for the stem form of 
the plant. The leaf of the Calamites was found and 
identified after the stem had been described and put 
into several species of Annularia. Some of these leaves 
are very dainty and could well be used by artists for 
decorative purposes. 
There were no flowers of the kind we have now in 
the swamp forests, and the vegetation was monotonously 
green, brown, and yellow, unrelieved by the brighter 
colors of red, blue, and purple. A great silence pervaded 
the world of that time, for there were no birds singing 
in the trees; no butterflies, nor bees, nor flies humming 
through the air. The only sounds which broke the quiet 
were the croaking of small reptiles and the faint buzz 
of gigantic dragonflies whose wing-spreads often reached 
thirty inches across. They were the most conspicuous 
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