PREFACE. 



THE present work is a record of a series of researches which I 

 have been engaged in carrying out, with intermissions, for some 

 years, into the minute structure and relations of the Palaeozoic 

 " Tabulate Corals." The space, means of illustration, and 

 leisure at my command have not permitted me to make this an 

 even approximately exhaustive account of the numerous and 

 interesting forms of Corals embraced by Milne-Edwards and 

 Jules Haime, under the name of " Zoantharia Tabulata." I 

 have, therefore, restricted myself, in the meanwhile, to the 

 elucidation of the anatomy of the principal Palaeozoic genera of 

 the " Tabulata," which I have been able to personally investi- 

 gate ; and I have usually given in addition short descriptions 

 of one or more of the species of each genus, as illustrative of 

 the structural type under consideration. 



The general result of my investigations is that I am able 

 to corroborate the views of Verrill and Lindstrom as to the 

 necessity of abolishing the " Tabulata " as a distinct and 

 separate division of the Zoantharia. I have also been led to 

 conclude that under the old name of "Tabulata" there are 

 included at least twelve distinct groups of corals, and that, 

 while some of these are Hydrozoa, and others are true Zoan- 



