PREFACE. 



In issuing this Decade to the Public, justice requires that I should 

 express the great obligations of this Establishment to Sir Philip 

 de Malpas Grey Egerton, who had previously undertaken and 

 completed two similar works at the request of my predecessor. 

 Sir Henry T. De la Beche. 



The present Decade contains descriptions and figures of six new 

 genera of Fossil Fishes, three of which had been named by Agassiz, 

 but not described or figured. 



In these three Decades of Fossil Ichthyolites, Sir Philip Egerton 

 has described nine new genera and thirty-five species ; and in call- 

 ing attention to his valuable labours, I beg especially to notice the 

 very skilful execution of the Plates by Mr. Dinkel, whose truthful 

 delineations of detail, combined v/ith artistic effect, cannot be 

 surpassed in this branch of Palseontography. 



RODEKICK I. MURCHISON, 



Director. 



Museum of Practical Geology, 

 l^tJi November 1857. 



