'^, 3 H 



COLUMBIA UNIVERSITY BIOLOGICAL SERIES. II. 



Amphioxus and the Ancestry 

 OF THE Vertebrates 



BY 



ARTHUR WILLEY, B.Sc. 



Tutor in Biology, Columbia College; Balfour Student of the 

 University of Cambridge 



WITH A PREFACE 

 HENRY FAIRFIELD OSBORN 



MACMILLAN AND CO. 



AND LONDON 

 1894 



All rights reserved 



