A 



CONTENTS 



SECTION XllI 



Phylum Chokdata 



Sul)-phylum and Class T. Hemichorda (Adelochorda) 



Sub-phylum and Class II. Urochorda 



1. Example of the Class— J. Acirfia . 



2. Distinctive Charactei-s and Classification 

 Systematic position of the Examjjle . 



3. .General Organisation .... 



Sub-phylum III. Euchorda 



Section I. Ackania . 

 Section II. Craniate 



Class I. Cyclostomata .... 



1. Exampls of the Class — Petromyzon . 



2. Distinctive Characters and Classification 



3. Comparison of the Myxinoids with the L; 



4. General Remarks 



Class II. Pisces 



Sub-class I. Elasmobranchii 



1. Example of the Sub-class — Sri/lliinn <i 

 modest un I 



2. Distinctive Characters and Classification 



3. General Organisation 



imprey 



iilciih( or Hemisci 



ill I mil 



•AOE 

 1 



14 



14 

 21 

 24 

 24 



43 



44 



65 



123 



124 

 137 

 138 

 142 



144 

 144 



144 



166 

 170 



