QUATERNARY OR RECENT PERIOD. 171 
” 
which low islands rose crowned with palms, ie the savage shark and 
sword-fish swam im the surrounding waters ; the elephant ranged through 
the tall groves on shore; the hippopotamus wallowed in the fresh-water 
lakes ; the Thinoceros: crashed through rank jungles; the mastodon, 
mammoth, and tapir trod in forests of palm ; and the wild ox and buffalo 
roamed over wide grassy prairies. 
2. THE Co~tp TERTIARY PrRiop.—Immediately above 
described, with» these strange organisms that speak of © 
are found remarkable accumulations of sand, often found p 
gravel, and clay interspersed with rounded worn boulders, k 
4 
+. ¥ 
e strata just 
rm climate, 
‘in hillocks; 
- under 
_ 




























. 1 = 
Seale of ames; Fee 
Fig. 94,—Megatherium. 
: : a wt 
the general title of the ‘Boulder: Clay,” some of the boulders being of 
: wth: . 
enormous size. From vy ee yhenomena, as shewn in a former chapter, 
it has been. proved tha cli 
: mate became arctic in character, and our 
country and others envelope rom shore to shore in a vast ice-sheet, like 
the Greenland of to-day. From the ends of this huge‘ice mantle, immense 
masses broke a and lose away icbons ‘By and by, however, the 
~ a 

