NEW INTERPRETATION OF CNIDARIA 243 



ends represents the starting point not only in the evolution 

 of Hydroidea or Hydrozoa but also of Cnidaria as a whole. 

 It is quite possible that we have here two parallel lines of 

 evolution both of which end in very speciaHzed solitary forms ; 

 once with Hydrae, the other time with Branchiocerianthinae. 



The Rank and the Position of Cnidaria 

 in the Animal Classification 



According to our interpretation, Cnidaria represents a 

 blindly ending side branch on the main stem of Turbellaria. 

 The Cnidaria assume the position or the category (taxon) of a 

 class within the stem (phylum) of Ameria. Thus the three sub- 

 groups, Anthozoa, Scyphozoa, and Hydrozoa, are in reality 

 three subclasses. A graphic representation of this position and 

 of their division will be found in the final chapter of the 

 present study. 



The Cnidaria with this, as we believe, well-founded, connec- 

 tion with Turbellaria to which we will later return, lose the isolat- 

 ed position they have enjoyed till now. It seems to us therefore an 

 exaggeration when they are given the rank of a phylum, as has 

 recently been done by Hyman, by Kastner, and by numerous 

 other scholars. I consider that the category (taxon) of a 

 phylum should be used less Hberally and that the number of 

 phyla must be limited to the absolute minimum. I will later 

 show that a very small number of recent phyla is in reaHty 

 fully sufficient (thus the Eumetazoa can be divided well enough 

 into four phyla). Usually we will find the taxon of a "class" to 

 be satisfactory. 



As a welcome side effect of the new classification which 

 tries to avoid the high categories of Radiata and Coelenterata 

 (after the system by A. S. Pearson, the editor oi the Zoological 

 Names, etc., prepared for the Section of American Association 

 for the Advancement of Science, Durham, N. C, 1949), we 

 find that the whole animal system becomes considerably 



