ITS CHARACTERISTIC ANIMALS. 
203 
VI ic Bivalves also have the same resemblance 
to the present ones, including fresh-water Mus- 
sels, as the marine Clams and Oysters. Among 
Radiates, the higher Echini (Sea-Urchins) have 
become numerous, while the other Ecliinoderms 
of all families abound. Corals include, for the 
first time, the more highly organized Madrepores. 
In the Tertiaries we see the dawn of the pres- 
ent condition of things, not only in the character 
of the animals and plants, but in the height of 
the mountains and in the distribution of land and 
sea. 
Let us give a glance at the continents whose 
growth we have been following, and see what 
these more recent geological epochs have done 
for their completion. In Europe they have filled 
the basin in Central France, and converted all 
that region into dry land ; they have filled also 
the channel between France and Spain ; they 
have united Central Russia with the rest of Eu- 
rope by the completion of Poland, and have 
greatly enlarged Austria and Turkey ; they have 
completed the promontories of Italy and Greece, 
and have converted the inland sea at the foot of 
the Jura into the plain of Switzerland. But this 
fruitful period in the progress of the world, when 
the character of organic life was higher and the 
physical features of the earth more varied than 
ever before, was not without its storms and 
