THE INTERNATIONAL SCIENTIFIC SERIES. 



AN INTRODUCTION 



TO THE 



STUDY OF ZOOLOGY, 



ILLUSTRATED BY THE 



CRAYFISH 



BY 



T. H. HUXLEY, F. E. S. 



COLLEGE ""OF DENTISTRY 

 UNIVERSITY OF CALIFORNIA 



WITH EIGHTY-TWO ILLUSTRATIONS. 



NEW YORK AND LONDON 



D. APPLETON AND COMPANY 



1920 



