78 THE OPEN BOOK OF NATURE 
twisted into long spires; they are called J'urrilites 
(Latin, turris=a tower). Still others were hooked, 
but not coiled at one end like Ancyloceras ; they are 
called Hamites (Latin, hamus=a 
hook). Both kinds flourished in Cre- 
taceous times (see Figs. 26 and 27). 
This chapter is sufficiently long, 
and I have found my space all too 
short. I had hoped to condense all 
I wished to say about fossils into 
one chapter, but this turns out to be 
an impossible task. I must there- 
fore continue the subject in another 
chapter, in which I shall give you a 
é _ short account of some of the higher 
Se forms of life which are found in 
se Beet cnied fossil conditions. When I come to 
(CRETACEOUS). tell you about some of the extinct 
monsters I am sure you will think 
that I have introduced you into the wonderland of 
geology. If you have followed the present chapter 
carefully and intelligently, you will have learned 
that the earth has been inhabited from a far, far 
time by hosts of curious and interesting animals. 
Indeed, it is difficult for us to imagine a time when 
the earth had no occupants, although such a con- 
dition of things must have existed incalculable ages 
ago. 
By the way, I ought to have told you that the 
study of fossils is called “ Paleontology ” (Greek, 
palaios = ancient, onta = existences). 
