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CONTENTS 



PART I. 



ON THE NATURE AND RELATION OF MONOCARDIAN 

 ANIMALS ; AND MORE ESPECIALLY FISHES. 



CHAPTER I. 



Preliminary Remarks. — On the general Nature and ^Relations of Mono- ^ 

 cardian Animals . - ^ - Page 1 



CHAP. XL 

 On Fishes in general • - - - 11 



CHAP. III. 



A Sketch of the History and Bibliography of Ichthyology, with some Re- 

 marks on collecting and preserving Fishes - - - 54 



CHAP. IV. 



On the Systematic Arrangement of Fishes - - - 72 



CHAP. V. 



On the Natural Arrangement of Fishes, the Primary Types of Form, and 

 the Analogies they present to other Classes of Animals - - 99 



CHAP. VI. 

 On the Order Cartilagines, or Cartilaginous Fishes - - 118 



CHAP. VII. 



On the Plectognathes, or Cheloniform Order - - - 189 



