iv PREFACE. 



incongruous opinions in physiology, let not their value be underrated, for it may 

 reasonably be presumed, that the modifications of arrangement, which remain 

 undiscovered, will harmonise the whole, and demonstrate the simplicity of unerring 

 truth in this portion of the manifold and wonderful designs of the Creator. 



In this Second Edition the letter-press lias been carefully revised and rendered 

 more concise. The descriptions belonging to each class of animals have been 

 kept more separate and distinct. The plates remain exactly the same, but as* 

 particular drawings appeared to have been cramped by the limited size of the page 

 in the first edition, a larger paper has been used in the present publication. 



6, TAVISTOCK SQUARE, 

 April, . 1864. 



