PREFACE. ix 



obtained will not be arrived at except by those who are willing 

 to adopt the modes of investigation here followed. l 



To those acquainted with the subject, it is unnecessary for 

 me to point out that I have been greatly assisted in the task I 

 have attempted by the previous labours of Milne- Edwards and 

 Haime, Martin Duncan, Lindstrom, and other distinguished 

 palaeontologists, and especially by the investigations of Louis 

 Agassiz, Verrill, and Moseley into the structure and relations 

 of the few existing Tabulate Corals. At the same time, almost 

 all the actual facts recorded in this volume have been verified 

 or worked out by myself, and any facts which I have not per- 

 sonally been able to test are invariably accredited to their 

 original authority. 



In this connection I should further add that I have not 

 been able to refer to the fifth volume of the ' Palaeontology of 

 New York,' by Professor James Hall, which, I believe, con- 

 tains numerous illustrations of Palaeozoic Tabulate Corals ; 

 the cause of my inability to consult this important work being 

 that, after repeated attempts, I found it impossible to obtain a 

 copy through the ordinary channels. Under these circum- 

 stances I can only leave it to my fellow workers to decide how 

 far a scientific work, which apparently cannot be obtained by 

 purchase, is to be regarded as actually published ; and in 

 making this remark I need hardly say that I am merely 

 anxious to account for an apparent omission on my part, 

 and do not wish to express any opinion upon the method in 

 which Professor Hall has seen fit to bring out his work. 2 



1 In this connection I may specially refer the reader to the remarks made at p. 

 270 as to the proper method of sectioning the coralla of the Tabulate Corals, with a 

 view to microscopic examination. 



s The work here referred to appeared, I believe, in 1877. With regard to its 

 publication, Professor C. A. White states (Bibliography of N. Amer., Invert. Pal., p. 

 38, 1878) that he had been unable to consult a copy, "search for it in the libraries 

 of Washington and Philadelphia having been unsuccessful." He adds : " Only one 

 hundred copies are reported to have been published." 



