750: Evolution in the Vegetable Kingdom. [August, 
gate the Medullosz to the ferns, the former of these types has a 
meager representation, but Renault admits Cycadoxylon in that 
formation, and Cyclocladia ornata occurs at Saarbrücken, while 
Schenk finds a true Pterophyllum in the coal flora of China. 
The presence of monocotyledons in the Carboniferous was 
long disputed, based as it was upon certain palm-like trunks de- 
scribed by Corda from Radnitz. But we now have one species 
of Palzospathe whose monocotyledonous character has not been 
questioned. The problematical sporangium, too, formerly sup- 
posed to occur no lower than the Permian, has now been found 
in the Carboniferous of St. Etienne, of Wettin, of Mazon creek, 
Illinois, and of Pittston, Pennsylvania, while so skeptical an 
author as Nathorst, in one’ of his latest works, defends its claims 
to be called a monocotyledon. 
Thus we find that all the leading groups or types of vegetation, 
except the dicotyledons, had made their appearance at the close 
of the Carboniferous age. Before passing to that important sub- 
class of the vegetable kingdom, the Ligulate and the Gnetacee, 
though numerically unimportant, deserve notice because they 
have been regarded by some as transition forms connecting the 
great types. 
The Ligulate are allied to the Lycopodiacez, and the genus 
Selaginella has sometimes been placed in the one and sometimes 
in the other of these orders. It is claimed to have been found in 
the Carboniferous, but of this there is doubt. Its first certain 
appearance is in the Cenomanian beds of Atane, Greenland, but 
‘it also occurs in our Laramie group at Golden, Colorado, and at 
Point of Rocks station in Wyoming Territory, The more typi- 
cal ligulate genus, Isoetes, makes its first appearance in our Eo- 
cene at Florissant, Colorado, and is Bic eee by two Miocene 
species in Europe. 
As regards the Gnetacez, by far the most ancient known rep- 
resentative is Heers Ephedrites antiquus, from the Odlite of 
_ Siberia. Only two other fossil species of this order are known, 
: ~n ers (Ephedrites) sotzkiana (which not only occurs in the 
o, zocene of Sotzka, but in several of the principal Miocene beds . 
oe of Switzerland, fria wd me = Ephedra johniana from 
leone rst 
ance of all other forms of plant life from that of the didoryledons 
