420 ELEMENTARY GEOLOGY 
It is in the land life that the greatest progress is 
noted. Here for the first time are found extensive rec- 
ords of plant life (Figs. 242 and 243). The conditions 
of the Carboniferous were unusually favorable for the 
preservation of these records. Extensive swamps bor- 
lig. 211. 
A group of Carboniferous crinoids. 
(1, Cyathocrinus lyoni; 2, 3, 4, and 5, Scaphiocrinus aequalis; 6, Poteriocrinus — 
decadactylus ; 7, Onychocrinus exculptus.) 
dered the land, and upon these, plants grew and died, and 
were later buried and preserved (p. 460) Many kinds 
of vegetation now extinct, and many now represented 
by small species, such as the fern, in that period grew 
to the height of large trees. The forests of the Car- 
boniferous time did not resemble, in any detailed 
