PROF. P. M. DUNCAN ON CYATHOPHYLLUM FLETCHERI. 175 
under it belong to two divisions of the family Cyathophyllide. The 
Cyathophyllide with large tabule and short septa have been sepa- 
rated from the genus Cyathophyllum, whose species have the septa 
passing to the axis of the corallum, and have been arranged under 
the genus Campophyllum, Hd. & H.; but it is too specific a distinc- 
tion to be of generic value. It is therefore pr oposed to place all the 
species of Palwocyclus in the genus Cyathophyllum.” 
The genus Paleocyclus may theretore be abolished altogether, 
and its species be named as follows :— 
1. SO aa porpita, Linné, | 3. Cyathophyllum Fletcheri, Ed. 
odal, Eu 
2. Edwardsi (P. rugosus, Hd. 
& H.). 
- preacutum, Lonsdale, sp. | 4. 
The third report (1871) on the British Fossil Corals alludes to 
the absorption of Paleocyclus by Cyathophyllum. 
The finding of the species C. Fletchert in the Wenlock-shale 
workings occurred during an investigation, the results of which have 
been published by another Society, into the nature of the synapticulee 
of Fungia, a genus of Fungide, and I was tempted to go over my 
work again, and to reconsider my opinion that the corals placed by 
MM. Milne-Edwards and Jules Haime in the Fungide, and called 
by the generic name of Palcocyclus, were rugose corals. 
The calice of such a type as the species named C. porpita is very 
open and shallow, and the septa are very visible. Now they are 
separate and do not ever unite by their sides, after the fashion of 
simple Fungide, but they have decided swellings on their sides 
which dip down and line the flanks of each septum down to the 
base. 
A section made longitudinally through the corallum shows these 
swellings to be a number of more or ieee vertical and slightly curved 
continuous lines on either side of each septum. They extend from 
the free upper margin of the septum to near the base. 
Omitting all reference to other structures, it is evident to those who 
have studied the synapticule of a recent Hungia, that the distin- 
guished French zoophytologists were not without some reason in their 
classification. But itis clear to me now, as it was in 1867, that 
these curved ridges did not meet in the interseptal loculi, and all 
the sections prove that there was no fusing or connexion in any way 
after the manner of synapticule. With regard to the other struc- 
tures, sections show that the axial space is bounded below by a 
dense wall-like structure, which is imperforate; I have not seen 
any tabule beneath the floor of the calice in the species Porpita; 
and I disagree with those paleontologists who persist in retaining 
the name Palwocyclus to express a Silurian Fungid. 
There are dissepiments between the septa close to the axial space. 
In the. other species of the group, takimg that species named 
C. rugosum (my Edwards:) as the type, the “ornamentation closely 
resembles that of the species just mentioned, except that the septa 
are less beaded. Sections prove that they have tabule, and of 
