26 VINE : CLASSIFICATION OF THE PALEOZOIC POLYZOA. 
accordance with Hiiicks and Smitt. These authors suggested that 
all future grouping of the Polyzoa should be based on the character 
of the " cell," or Zocccium, rather than upon the mode of growth of 
the " colony " or Zoarium. In his work on British Marine Polyzoa 
Mr. Hincks says, "there is evidence ('I quote my own words from 
Brit. Assoc. Report, p. 2 of Report), however, (as I learn on the 
excellent authority of Mr. R. Etheredge, jun.), of the existence of a 
few Chilostomatous genera at least, within this epoch (Palaeozoic), and 
probably the group is represented in the Silurian division of it,' a 
conclusion, which after the most careful research, I am unable to 
agree with."* In dealing with the Palaeozoic genera, however, I was 
obliged to accept the dictum of other authors, hence I took Lonsdale's, 
Nicholson's and Messrs. Young's estimate as to what external 
characters were found in Fenestella, Ptilodictya and Glauconome, 
and worked accordingly, but none of the remarks which I offered in 
the reports were wholly founded upon the labours of others. T}^es 
of the various genera were sectioned, but not, perhaps, fully under- 
stood in all their details of structure. I was not at that time, 1879 
and 1880, aware of the rich harvest of Palaeozoic forms which was 
then being catalogued, and which have since been described by Mr. 
E. 0. Ulrich, of Cincinnati. Had I been aware of these I should have 
been more careful before committing myself to a peculiarly British, 
rather than a general classification. I hope, therefore, future 
students of Palaeozoic Polyzoa will bear these remarks in mind while 
reading over the observations I offer on my own and Mr. Ulrich's 
labours. 
In the year 1881 Mr. G. W. Shrubsole, of Chester, began the 
compilation of his paper on Glauconome, and as he had had some 
communications with Mr. R. Etheredge, jun., besides mj^self, respect- 
ing Palaeozoic forms, Carboniferous and Silurian, I suggested to him 
the necessity of a new arrangement of the so-called Cyclostomatous 
forms. Mr. Slirubsole's idea was to suppress the upper Silurian name 
* In tlie report, details will be found of all the supposed species whose 
aflBnities were somewhat; doubtful. Since this was written I have been compelled 
to modify this opinion, and in all probability examples both of Chielostomatous 
and Ctenostomatous Polyzoa existed in Palasczoic strata. 
