PREFACE 
OwING to unforeseen circumstances, not unconnected with the 
foundation of a new University, the publication of this volume 
has been unduly delayed. Some parts of the work have actually 
been in type for more than four years ; and although the authors 
have made every etfort to keep them up to date, the arrangement 
is naturally not quite what it might have been if the articles 
had been written immediately before publication. 
In view of the novelty of My. Boulenger’s classification of 
the Teleosteans, and of the fact that several independent workers 
have been occupying themselves with the subject during the 
last year or two, it is fair to state that this part of the volume 
was completed in 1902. Professor Herdman’s account of the 
Ascidians was ready for publication two years earlier. 
Professor Bridge wishes to express his best thanks to Dr. 
R. H. Traquair, F.R.S., for his kindness in reading the proofs of 
the pages which deal with the fossil Crossopterygii, Chondrostei, 
Holostei and Dipnoi, and for much helpful advice and criticism ; 
to Mr. G. A. Boulenger, F.R.S., for his valuable and suggestive 
criticism on certain points; and to Mr. Edwin Wilson, for the 
care which he has taken in the preparation of the figures. 
July 1904. 
