22 
VINE : CLASSIFICATION OF THE PALAEOZOIC POLYZOA. 
including the whole of the recent, semi-recent, and Mesozoic Polyzoa, 
under a description so well worded as the above. Most of the 
species that have come under my own observation may be definitely 
described as Cyclostomatous. The cells are tubular, the orifices in 
most cases are terminal, and though not all of the same diameter as 
the cell, the orifices are certainly without any " moveable " apparatus, 
still there were cell "closures" in Cyclostomatous, as well as in 
Cheilostomatous Polyzoa. It is not altogether then the preciseness 
in the above definition that causes any difiiculty to tlie Palaeon- 
tologist, whenever his investigations carry him beyond the Mesozoic 
horizons. For accurate descriptions of species here, however, the 
diagnosis is either too incomplete or too obscure, and this is felt to 
be the case by every naturalist who has taken the Palaeozoic Polyzoa 
in hand. 
I have already referred to the labours of Mr. Waters on the 
semi-fossil, and fossil Cyclostomata,'" but it will be necessary to refer 
to them again for the purpose of formulating a satisfactory nomen- 
clature for speculative as well as for working students. 
The Oyclostomatons CelV (Busk) Zooecium" (Hincks) "is 
the chamber in which the polypide is," or was lodged. It is wholly 
calcareous, and its structural elements are few and characteristic. If 
we take the cells " of two species, Crisia and Hornera, and analyse 
them, we shall find material for formulating a definite working 
nomenclature, suitable for Palaeontological investigations ; then, if 
some few of the Palaeozoic species are submitted to the test, it will 
soon be found whether the ancient cell corresponds with the 
characteristic recent cell in all, or in any, of its elements. If not, 
then the question naturally arises as to whether it is wise to confine 
ourselves to one division for the Polyzoal group of organisms, or 
whether it will be necessary to establish other divisions in which 
many of the Palaeozoic species can be satisfactorily placed. 
In the cell of Crisia, {cmiiuta, ehurnea, or denticulata) there are 
certain " punctures " evenly or sparsely distributed, which do not 
appear to have been separately studied either by Mr. Busk, or Mr. 
Hincks, but the punctures are partly referred to as characteristic of 
♦ Proc. Yorks. Geol. and Polyt. Soc„ pt. iii., vol. 9, 1888. 
