ON FOSSIL POLYZOA. 177 
and many of the species of the Ceriopora of Goldfuss are redistributed. 
The following is his family grouping :— 
A. Tusutiporina, Milne-Ed., with 9 genera 
B. Crrroporma, Bronn Nine |W eines 
C. Satprncina, Hagenow See cone 
D. Urcronata me POs fs, 
The last family contains nearly ninety species, and is largely the 
equivalent of the CuEILostomata, Busk, the first two families representing 
the Cyctosromata of Busk. 
1852-1859. Mr. Grorce Buskx. 
‘Catalogue of Marine Polyzoa’ (‘ Brit. Mus. Cat.’ pt.i. and ii., 1852) ; 
‘ Monograph of the Foss. Polyzoa of the Crag,’ 1859. 
One of the earliest and best classifications of the Polyzoa as a distinct 
group is that furnished by Mr. Busk in the second of these two works. 
As much, however, of the introduction and synoptical arrangements has 
more direct reference to a suborder that is very poorly represented in 
strata below and in the Cretaceous, I may be allowed to pass this over 
and confine my remarks to the second suborder, Cyyclostomata, Busk. In 
the synoptical arrangement of this group Mr, Busk included genera 
belonging to the Mesozoic and Cainozoic epochs only; except in a few 
rare cases, there was no provision made for Paleozoic genera or species. 
In speaking of his own labours Mr. Busk says: ‘Owing to the great 
comparative simplicity and uniformity of conformation in the individual 
cells, and the absence for the most part of adventitious organs such as 
ovicells and vibricular or avicularian organs, our principal reliance in 
the distinction of genera and species must be placed on the general form 
of the zoarium’ and the mutual relation of the cells; but as in many cases 
these vary very greatly in different portions of one and the same zoarium, 
it often happens, more especially in fossil forms, that it is almost im- 
possible to determine whether two apparently distinct things may not 
be referable to one and the same species. These observations apply more 
forcibly perhaps to Pustulopora, Idmonea, and Hornera, than to any other 
genera, but should be taken into account in several others also.’ 2 
SyNopricaL ARRANGEMENT OF CYCLOSTOMATA, 
§ I. Articulate s. radicate. 
Family Crisup%, Crisia, Crisidea. 
§ Il. Inarticulate: et adfixe. 
a. CELLULIS DISTINCTIS. 
Family IpMonripZ. 
Genus Hornera. Genus Cyrtopora. 
»  Terebeliaria. »,  Idmonea. 
» Cricopora. »  Pustulipora. 
Family Tuputiporipa. 
Genus Mesenteripora. Genus Alecto. 
5, Tubulipora. 
' « Polyzoary,’ Busk. 2 The Crag Polyzoa, p. 90, 
1883. N 
