30 
RECORDS OF THE AUSTRALIAN MUSEUM. 
On the OCCURRENCE of the GENUS COLUMN ARIA in the 
UPPER SILURIAN ROCKS of NEW SOUTH WALES. 
By R. Etheridge, June., Curator. 
(Plate viii.) 
I believe I am correct in stating that Columnaria has not so far 
been recognised as an Australian genus of Paleozoic Corals. When 
1 had the pleasure of examining the Museum at St. Stanislaus 
College, Bathurst, a few months ago, under the guidance of the 
Rev. Father Dowling, I observed a coral from Molong, that I 
took to be Columnaria from macroscopic characters only, sub- 
sequently confirmed, however, by microscopic. At any rate if 
the coral in question be not a species of this remarkable genus, 
then the candid confession of my ignorance as to its systematic 
position must be made. Father Dowling courteously allowed me 
to divide the specimen, a portion of which is now in the Australian 
Museum. 
The composite corallum (PI. viii., Fig. 1) is small, hemispherical, 
but whether flat, rounded, or subpedunculate at the base, I am 
unable to say. The colony only measures about two inches square, 
and is thus even less than in C. calicina, Nich. The surface is 
covered with shallow polygonal calices that are circumscribed by 
prominent margins, crenulated by the strongly marked septa very 
distinctly visible in a weathered specimen. The eorallites are 
closely compacted, contiguous, and completely united by their walls. 
Tetragonal, quadrangular, pentagonal, hexagonal, or even irregular 
eorallites were observed, in contact throughout their entire course, 
without any partial separation, even near the mouths as in C. 
calicina , Nich,, or some conditions of C. alveolata , Goldf. In 
thin sections prepared for the microscope, the walls are found to 
be composed of uniform grey sclerenchyma (stereoplasma), with 
only here and there any trace of a primordial wall separating 
them as a thin brown line ; the amalgamation is therefore so per- 
fect that nearly all trace of primordial demarcation is practically 
lost. Thus, in one instance, there is to be noted a decided depar- 
ture from the microscopic structure of Columnaria described by 
Nicholson.* The eorallites have a very constant diameter of one 
millimetre. In longitudinal sections (PL viii. , Fig. 7 ) the same appear- 
ances are visible, the eorallites also presenting the narrow tube-like 
structure of the Favositida?, but without the mural pores of the 
latter. There are only sixteen septa, equally divided into primary 
and secondary, the former extending across the visceral chambers 
* Tabulate Corals Pal. Period, 1879, p. 192. 
