76 VINE : BRITISH PAL/EOZOIC CTENOSTOMATOUS POLYZOA. 
The evidence, however, on which I rely for more faithful deter- 
mination is derived from the study of several hundreds of examples 
brought to light in my close and careful examination of the organic 
debris of the Wenlock Shales. I have already described many of 
the organisms found in Mr. Maw's washings", but there still remains 
several groups to work out more carefully than I have yet been able 
to do, and in all probability this will form an initial paper of a far 
more elaborate series than I have previously attempted. The reason 
for this may be briefly stated. In the various States of America 
details of the Palaeozoic faunas have been and are being published. 
Some of the Palaeozoic horizons are similar to our own, especially the 
Upper Silurian and the Sub-carboniferous, and the Polyzoa or Bryozoaf 
of these horizons have been more systematically worked out, des- 
cribed, and illustrated by American authors than by us. From time 
to time, as the work progresses, I am kept supplied with typical 
examples of species of the Bryozoa for comparison with our own, and 
also with the literature of the subject whenever published. For this 
reason many of the Wenlock Shale Polyzoa have been re-studied and 
many apparently allied forms separated for comparison and descrip- 
tion. The present group of organic forms, which 1 now place amongst 
the Ctenostomatous Polyzoa. as described by Hincks and others, is 
the outcome of matured knowledge and more careful selection. I am 
fully aware of the difficulties that I have to encounter in thus at- 
tempting to arrange systematically a series of fossils of such obscure 
types, especially when so many experts have failed. It may be well, 
therefore, to state briefly by what means I arrive at my present con- 
clusions. 
* See Geol. Mag., 1881, (Jan. and March) for remarks by Mr. Davidson and 
Mr. Maw. 
t In all my own writings I prefer to use the term Polyzoa rather than 
Bryozoa, not that I have any prejudice against the use of the latter. When- 
ever I use the words in unison, as above, I do so in deference to the opinions 
of others who differ from me. With Continental authors, however, the words 
Polyzoa and Bryozoa are generally speaking synonymous, but American 
authors frequently include under the head line Bryozoa forms which Professor 
Nicholson and others describe as Monticulipora, &c, or Cielenterata. In a 
modified sense, perhaps, American authors may be truer to nature than their 
British opponents. 
