FOSSIL HORSE-TAIL PLANTS 99 
point it out to you. Well, the Carboniferous Cala- 
mites were gigantic horse-tails. Imagine a horse- 
tail plant, say two feet high, such as you can see 
any day, magnified to the size of a tall poplar-tree, 
Fic. 39.—Fosstr Remains oF CARBONIFEROUS PLANTS. 
a, Calamites canneformis. c, Sigillaria reniformis. r 
b, Alethopteris lonchitica d, Lepidodendron elegans. 
(fern). e, Stigmaria ficoides. 
but retaining its horse-tail appearance, and you 
can form an idea of the Calamites of which fossil 
remains are found quite as commonly as those of 
the Lepidodendron. 
