120 
In the original diagnosis of this genus by Ten.-Woods,* pali 
were supposed to be present, but the structures observed are 
merely the lobed or thickened ends of some of the principal 
septa. By Duncan they are called paliform lobes or dentations 
around the axial space. An amendment of the genus proposed 
by the latter author} was based upon Woods’ drawings and 
description of 7. fenestratus, the only species then known. To 
him is due the recognition of a third cycle of rudimentary septa 
answering to the third cycle of well developed costz, but in some 
other respects his description is incorrect and misleading. The 
perforated wall, which is questioned by him, is, nevertheless, 
undoubted, and forms an essential characteristic of the genus. 
In regard to this I entirely concur with Woods, who remarks— 
“The pores go right through the wall; in fact, as the pores are 
very large, the portion of the wall which separates them becomes 
little more than a flat transverse bar.” I may add as confirmatory 
of his conclusion, that a longitudinal section of the coral, pre- 
pared so as to leave a portion of the wall intact, admits light 
freely through the pores. Duncan follows Woods in stating that 
there is no columella. As further detail, he adds—‘“ The septa, 
which are large and equal, extend. close to the axial space, and 
form a tube-like space.” The equality of the septa is evident 
enough from Woods drawings, his assertion to the contrary in 
the accompanying description being a mistake. The tube-like 
space is, however, not vacant, as might perhaps be inferred, but 
filled with hard nodular tissue, which, uniting with the septal 
ends, forms a columella. This is visible also in transverse 
sections of the corallum, cut either near the upper surface or 
close to the base. As to which of the two principal orders of 
septa should be considered the primary is not easily decided. I 
am inclined to reverse the order of development assigned to them 
by both the authorities quoted. In the new species described 
below, the lobed septa are, I judge, those of the second order. 
Notwithstanding its perforated wall, the genus was placed by 
its author among the Turbinolidz on account of its supposed 
analogies with certain genera in that family. The second species 
referred to shows, however, in addition to a distinctly perforated 
wall, a regular fusing together of certain septa in each system at 
some distance from the margin, as in the genera of the 
Kupsammide. I can, in fact, see no reason for the retention of 
the genus in the Aporosa Section of the Madreporaria, and place 
it instead under the Perforata. The regular perforations in the 
* Proc. Royal Soc., New South Wales, vol. XII., 1878, p. 59, fig. 2. 
+ Revision of Madreporaria. Jour. Linn. Soc., Zoology, vol. XVIIL., 
pp. 20, 21. 
