﻿PREFACE. 



Since the completion of Part I. of this Catalogue in 1889, nearly 

 two years have elapsed, during which time great progress has been 

 made in the examination and careful study of the Collection of 

 Fossil Pishes; while Mr. Arthur Smith Woodward has had the 

 additional advantage of visiting the principal Museums of Scandi- 

 navia, Russia, Austria, Germany, the United States, and Canada. 

 A knowledge of the " types " contained in other Museums is essen- 

 tial to a correct interpretation of our own specimens, and much of 

 the merit of the present volume may be attributed to this fact, and 

 to the wider experience gained by personal interchange of views 

 with ichthyologists abroad. 



Special attention has also been paid by the author to the careful 

 collation of the very extensive and widely scattered literature of his 

 subject, as amply testified by the very copious references which 

 occur throughout this Catalogue. 



The present volume commences with the Acanthodii, which are 

 shown, by preponderating evidence, to belong to the Elasmobranchs. 

 The Chimceroidei come next, the most important forms being those 

 of Squalor aja and Myriacanthus ; while Ischyodus and Edaphodon 

 are represented by a fine series of jaws. Next follows the very 

 large collection of " Ichthyodorulites " (fish-spines) belonging to 

 Elasmobranch and Chimseroid fishes, but not definitely placed in 

 any group. To these succeed the Ostracodermi, notochordal fishes 

 with a well- developed exoskeleton, the head and anterior portion of 



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