.• LI 



PART I 



CERIANTHARIA 



Before entering upon the special matter of this Report a few remarks seem necessary 

 in explanation of the classification that has been adopted. The classification of the Anthozoa 

 has undergone many changes as increasing knowledge of the structural peculiarities of the forms 

 assigned to the group has revealed the manifold differences of their organization. An historical 

 review of these changes is unnecessary here, as I have already (1893) given an account of the 

 principal ones up to 1 89 1 , and a somewhat more thorough review, brought up to date, has 

 recently been given by Carlgren in the Anthozoa of Bronn's Thierreich (1908). Within recent 

 years two classifications have been proposed as the result of extensive studies of groups of the 

 Anthozoa and to these I desire to refer briefly, since the classification I am adopting here 

 differs from both in certain particulars while agreeing in others. One of these classifications is 

 that proposed by van Beneden (1898) and the other that of Carlgren, in the work just cited. 

 Van Beneden, after a thorough discussion of the questions at issue, divides the Anthozoa into 

 three great groups, the Zoanthactiniaria, Octactiniaria and Scyphactiniaria. The first of these 

 groups is again subdivided into the Zoanthinaria, equivalent to Hertwig's tribe Zoantheae, and 

 the Hexactiniaria which includes the Actiniaria and the Madreporaria. The Octactiniaria correspond 

 to the group more usually known as the Alcyonaria ; the Scyphactiniaria are divisible into three 

 subgroups, the Ceriantharia, including the Ceriantharia and the Antipatharia, the Scyphomedusae 



and the Rusfosa. In tabular form the arrangement is as follows 



Anthozoa 



Zoanthactiniaria . . 



Zoanthiniaria 

 Hexactiniaria 



Octactiniaria 



Scyphactiniaria 



Ceriantipatharia. 

 . I Scyphomedusae 



l Madreporaria 

 (Actiniaria 



(Ceriantharia 

 (Antipatharia 



5479* 



Rugosa 



SIBOG A-EXPEDITIE XV ö. 



