BRYOZUA FROM AUSTRALIA. 679 
There is in certain Chilostomata a tendency for one layer of 
zocecia to grow superposed upon the preceding one, as, for instance, 
in Schizoporella sanguinea, Micropora impressa, Moll. In Nodelea, 
from the Chalk, this is also the case, and upon this peculiarity the 
genus Multinodelea was founded ; but from specimens of Nodelea 
angulosa I collected from the Chalk of Royan it is clear that it 
occurs in both forms, and the same thing is frequently found in the 
Cyclostomata, and probably should but seldom be used as a generic 
character. 
In a specimen of Diastopora lamellosa, Mich., from the Oolite, 
there is the usual growth, consisting of two layers of zocecia growing 
back to back, but on one side there are two other layers superposed 
on the original one, 
This is not the place to fully discuss the various classifications 
of the fossil Cyclostomata, but none yet seems at all satisfactory. 
Beginning with d’Orbigny’s, although many of the principles adopted 
were undoubtedly good, yet he carried it out so unsatisfactorily that 
what is good in it has been too much neglected ; and coming next to 
Busk’s in the Crag Polyzoa we certainly cannot now accept any classi- 
fication which separates under two quite distinct divisions Pustulopora 
and Spiropora, the one falling under the section “cellulis distinctis ” 
and the other under that ‘ cellulis indistinctis,” and I must confess 
my utter inability to understand in the least what this division 
means, and what it is based upon. Again, while Drscoporella and 
Defrancia are united in one family, Pungella, Frondipora, and 
Fascicularia are placed in three ; and a study of Mr. Busk’s synop- 
tical table cannot fail to leave us impressed with the difficulty of the 
classification of the fossil Cyclostomata. Before the third part of 
the catalogue of British-Museum Bryozoa was written, Smitt’s 
classical work had appeared, and of course was to a large extent 
followed ; but I am inclined to look upon the removal of Defrancia 
from the Fasciculine as a slip on the part of Mr. Busk. 
Next comes the work of my friend Mr. Hincks; but the range 
of recent British Cyclostomata is so small that it does not help 
us much in considering general classification. I certainly cannot 
follow him at present in separating Hornera from [dmonea in the 
families Horneride and Tubuliporide. 
Althoughit would be impossible here to give a complete history of ail 
that has been attempted in the way of arrangement, we must mention 
the efforts of Dr. H. Hamm ; but certainly the thesis (Die Bry. des 
Mastr. Ober-Senon. 1 Th. Cyclost. Berlin, 1881), does not deal with 
the difficulties in a way which recommends itself to my mind; for it 
is not new genera and families that are wanted, but to show the 
connexion of those now used, instead of creating on a slender basis 
fourteen new genera of fossil Cretaceous Cyclostomata, where genera 
already exist in overwhelming superabundance ; and further his third 
type, the Stigmatoporina, is certainly doubttul, as it is largely, if not 
entirely, composed of Chilostomata*, Multelea magnifica, d’Orb., and 
* Hlea, Myriozoum and some others may possibly have to be grouped together 
as a division of the Chilostomata ; but, with opercula and avicularia, they have 
nothing in common with the Cyclostomata. 
4, Th ve 
