AUTHOR'S PREFACE Xiil 
with living forms, these creatures appear to us as “ monstrosities,” 
and may well find a place in our collection. 
The author wishes, in a few words, to thank those friends who 
have rendered him assistance in his task. 
Dr. Henry Woodward, F.R.S., Keeper of Geology, Natural 
History Museum, has from the first taken a lively interest in 
this little book. He kindly helped the author with his advice 
on difficult matters, criticising some of the artist’s preliminary 
sketches and suggesting improvements in the restorations. With 
unfailing courtesy he has ever been willing, in spite of many 
demands on his time, to place his knowledge at the disposal of 
both the author and artist; and in this way certain errors have 
been avoided. Besides this, he took the trouble to read through 
the proof-sheets, and made suggestions and corrections which 
have greatly improved the text. For all this welcome aid the 
author begs to return his sincere thanks. 
To Mr. Smith Woodward, of the Natural History Museum, 
the author is also much indebted for his kindness in reading 
through the text and giving valuable information with regard to 
the latest discoveries. 
The artist, Mr. J. Smit, notwithstanding the novelty of the 
subject and the difficulties of the task, has thrown himself heartily 
into the work of making the twenty-four restorations of extinct 
animals. To him, also, the author is greatly indebted, and 
considers himself fortunate in having secured the services of so 
excellent an artist. 
To the publishers his thanks are due for their liberality in 
the matter of illustrations, and the readiness with which they 
have responded to suggestions. 
With regard to minor illustrations the following acknow- 
ledgments are due :— 
