80 
RECORDS OF THE AUSTRALIAN MUSEUM. 
tabulate, the tabulae far apart (they are nearly half a mm. apart), 
although complete, the intertabular spaces vertically elongate, 
and both the walls and tabulae greatly thickened, (PI. xvii., 
fig. 7) as compared with the similar parts of the normal corallites. 
There is not the slightest trace whatever of the small projections 
in the interstitial tubes, £t apparently of a septal nature,” dis- 
covered and described by Nicholson.* 
The presence of the interstitial corallites, and the absence of 
septa clearly places the present coral within the group of 11. 
catenulatus , the “ Chain-coral” of the Wenlock, but as compared 
with the latter there is this remarkable difference. In H. catenu- 
latus the tabula? of the normal corallites are “ comparatively 
remotely disposed,” whilst in the interstitial tubes they are “much 
more numerous and more closely set.”f In our coral, which I 
propose to call Halysites australis , the exact opposite is the 
case. 
It is customary with Monographists to include in II. catenulatus 
a large number of other forms, in former days regarded as separate 
species, purely from external characters, but 1 think before this 
indiscriminate lumping is done, the whole of such forms should be 
submitted to microscopic examination, when possibly differences 
of an equally important nature to that shown above, may be found 
to exist. 
Halysites australis differs from //. ayglomerata , Hall,J by the 
same characters that it does from 11. catenulatus , Linn. In the 
form of the reticulations and mode of growth it is more akin to 
H. labyrinihica , Goldf.,§ and H. catenulatus , var Harti , Eth.,|| 
but in both cases the fenestrules are larger than in our species. 
The specimens were collected by the Kev. J. Milne Curran, at 
Molong, N. S. Wales, and by him presented to the Trustees. 
# Loc. cit., p. 229, t. 11, f. 1. 
f Ibid., p. 228. 
t Hall— Pal. N. York, ii., 1852, t. 35 bis. 
§ Petrefacta Germanise, t. 25, f. 5a. 
|| Quart. Journ. Geol. Soo., xxxiv., 1878, p. 583, t. 28, f. 2. 
