CONTENTS 
I 
Introductory. The form and movement of Fishes. Their classifica- 
tion; geological distribution; mode of evolution. The survival of 
@omeraused forms 6 we se tk tk 
II 
The Evolution of Structures characteristic of Fishes; e.g. (1) gills, 
(2) skin defences, teeth, (3) fins, and (4) sense organs . 2 
III 
The Lampreys and their Allies. Their structures and aie relation- 
ships. The Ostracoderms and Paleospondylus . . Tae 
IV 
The Sharks. Their plan of structure; prominent ee ves and 
extinct; their interrelationships. . . . ‘ ws 
V 
The Chimeroids. Their characteristic structures; their J esuoemanne 
and relationships . . 
VI 
The Lung-fishes. Their structures. Extinct and recent forms. The 
evolmson Of the group... 6 2. 6 s+ ee te te ht 
xi 
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