§ 34. 



EQUISETACEOUS PLANTS. 



715 



Lign. 155. — Calamites cannjefor- 

 mis ; from Coalbrook Dale. 



Calamites. The plants of this extinct genus, closely re- 

 semble the Marestail, but are destitute of the encircling 

 sheaths, and are uniformly stri- 

 ated longitudinally. They 

 are often forty feet long, 

 and three feet in diameter, 

 and are so abundant in the 

 coal, as to prove that they 

 constituted an important fea- 

 ture in the flora of the coun- 

 tries of the carboniferous 

 epoch.* Calamites have also 

 been found in strata below the 

 coal, and belong to the most 

 ancient terrestrial vegetation 

 of which any traces have been discovered. A fragment of 

 a small stem, with leaves, is represented in Lign. 155. 



Aster ophyllites. Plants 

 with vefticillate leaves 

 are common in the 

 coal-shales ; they have 

 been named Asterophyl- 

 lites, or Star-leaf. Some 

 of them resemble the 

 foliage of Equisetum or 

 Hippuris, but no cer- 

 tain conclusions have 

 been obtained as to the 

 nature of the originals. 

 Two of the usual forms 

 are here represented 

 (Lign. 156 and 158, Jig. 

 1). They are often 

 associated with seed- 

 vessels, which occur in 



Lign. 156.— Asterophyllites EauisETi- 

 formis ; from Coalbrook Dale. 



Medals of Creation, p. 110. 



