KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. l4. N:0O 6. 13 
3. Duncania barbadensis PoURTALES. 
RER 23: 
POURTALES in Results of the Hassler Exped. p. 44, pl. IX, fig. 5—7. 
Dredged up by Dr Goös off St. Martin in 40—50 fathoms, off Salt Island in 250—300 
fms, off Anguilla in 200 fms. 
This remarkable and beautiful little coral corresponds in its general form and 
some details with the description given by POoURTALES, but there are some differences 
in the structure, which may be here annotated. The specimens from the above stated 
localities are smaller than those from Florida, as the largest specimen from Anguilla 
measures only 15 millim. in height and 8 millim. in breadth. 
The total number of the septa varies between 18—21 and none of them can be 
"singled out as belonging to the first order: they are rather all alike.” Only those 
which have paluli in front of them are a little shorter. There seems to be no reason 
to class this species amongst the Rugosa, which commonly are considered to have four 
septa of the first order”). In making a thin section of the apex of a Duncania, I di- 
stinetly saw six septa of the first order, which meet in the centre. The diameter of 
this basal section was only one millimeter. The apex of the coral is filled with solid 
calcareous matter of quite the same nature as that which, in an earlier paper”) I have called 
stereoplasma. This is a secretion of the basal membrane of the animal, in some Way 
superseding or supplementing the dissepiment. The dissepiment may nevertheless exist 
in a caliele and later be absorbed by the slower advancing stereoplasma, as is the 
case in this Duncania. There are specimens (see fig. 23) which have two dissepimental 
rings near the outer wall, although the exterior one is partially covered up by the 
septal rim or border. The dissepiment is vertical. 
This species seems to enjoy a sort of propagation by schiziparity; at least most 
specimens show fragments of an older calicle, from which they bud. 
As to the name of this genus it may be remarked that DE KOonincK already, in 
1872, in his ”Recherches sur les animaux fossiles de la Belgique” p. 107, pl. XI, fig. 
1, founded a new genus of Rugose Corals under that denomination. In case now this 
fossil really proves to be a new genus and not, as seems likely, only a Zaphrentis, 
such as they often occur at Tournay, altered, and without any dissepiments, and with 
a central ring of stereoplasma, the genus Duncania of PoURrRTALES is to be abolished 
and a new name given. But until this point is settled, it is advisable to retain it, 
instead of adding to the confusion by creating a new name, which in the consequence 
may prove unnecessary. 
1) There are indeed very few of the Silurian corals that have four primary septa. Excepting Stauria there 
is scarcely any. Goniophyllum, in which the foursidedness is so strongly expressed, has in the beginning 
only one septum. Even specimens of the tiniest size, such as I have found for instance of Palxeocyclus por- 
pita L., of only 1,3 millim. in diameter, are already provided with 20 septa. 
2) Öfversigt af Vetenskaps-Akademiens Förhandlingar 1873, Svenska Under-Sihiriska koraller Sep: pr rad: 
