680) A. W. WATERS ON FOSSIL CYCLOSTOMATOUS 
others having distinct avicularia; and probably Meliceritites should 
be entirely abandoned. On the other hand, however, Dr. Hamm has 
done service in showing the importance of the manner in which the 
new zocecia arise in the colony. 
Mr. Vine has brought together in the British Association Reports 
a vast amount of material bearing upon the classification of Cyclo- 
stomata up to the age of the Cretaceous, and it must be of great use 
for future workers. For my own part I much doubtif we are yet in a 
position to frame anything approaching to a natural and final classi- 
fication of the older forms; but this opinion may arise from my 
extremely small acquaintance with Paleozoic Bryozoa ; but neither 
do I think we have nearly arrived at that point with the recent and 
neozoic forms, and until this is the case we can hardly expect to be 
quite sure about the older ones; and I have often urged upon my 
friend Mr. Vine that more information concerning the minute struc- 
ture would be most valuable from so good a worker. 
For my own part I must at present be content with making 
known further material which should be of some use in assisting 
towards more definite ideas of the group, and while I have given 
some indications as to various directions for investigation, a collection 
like the present, where many are not perfectly preserved, where few 
have ovicells, and where there is often only an isolated specimen, is 
not favourable for testing any system. 
However we attempt to arrange the Cyclostomata, the divisions 
are found not to be very distinct, and many of the genera generally 
accepted must be discarded. To take an example, the growth of a 
typical Spiropora, such as S. verticeallata, may seem marked enough to 
form a genus Spiropora; but in several specimens of Spiropora con- 
ferta, Rss., from Val di Lonte, there are parts of the colony where 
the complete circle of zocecia is most typical, whereas in other 
parts of the same colony the cells are arranged irregularly quincun- 
cially, and this is especially the case near the bifurcations. Here part 
of the colony might be determined as Spiropora conferta, Rss., and 
the other part as Entalophora pulchella;‘and on this account I have 
dropped the genus Spiropora and united: it to Hntalophora ; again, 
Filisparsa comes very near to Entalophora, and in its turn Filisparsa 
approaches such a form as Jdmonea irreqularis, Meneg., which is 
most difficult to place, as sometimes the cells are so distinctly serial 
as to give it every appearance of [dmonea, while at other times the 
appearance is that of Jlisparsa ; but the ovicell of the Mediterranean 
Filisparsa is on the front of the zoarium, and that of J. irregularis 
on the dorsal surface, which would seem to indicate that it should 
probably be relegated to Hornera. 
The available characters in the Cyclostomata being much fewer 
than in the Chilostomata, we are on this account not likely to find 
the first as useful paleontologically ; and further as they are less 
highly differentiated, it should not surprise us to find them more 
persistent through various periods; and Entalophora verticillata, 
which may be said to be as simple as any known form, consisting as 
