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10 
EUPSAMMIDÆ. 
GENUS BALANOPHYLLIA, Searles Wood. 
Balanophyllia dilatata, spec. nov. Pl. i., figs. 2а, b. 
The two examples of this species are attached to what is 
probably the lower encrusting portion of the thallus of Litho- 
thammion. Enclosed by the same, or built into it, there is 
evidence of foraminiferal tests; while its surface shows small 
patches of polyzoa. The coralla are about 10 mm. apart, but the 
widely spreading base of one of them slightly overlaps that of the 
other. ‘Lhe latter corallum (the figured example) is intact; but 
the former is fractured longitudinally, and the structure of its 
columella and septa is thereby well disclosed. The habitat of the 
specimen cannot be definitely given, but as Mr. Mulder found it 
amongst the dredgings of the late Bracebridge Wilson, together 
with Rhizotrochus radiatus, Cylicia rubeola, and other organisms 
common in Port Phillip Bay, there is, I think, no reason to doubt 
that it came from that locality. 
The corallum is sub-cylindrical and. not much compressed, of 
moderate height, and attached by a large spreading base with a 
slight constriction immediately above it. The costæ are separated 
by narrow interspaces, and consist of raised double lines with 
minute spines on their surfaces and numerous central pores ; the 
interspaces are also porous. The fractured example has a thin 
granular epitheca on the base and the lower fourth of the wall; 
but the other shows no vestige of this covering. The calice is 
elliptical and deep. The columella is large, longitudinally placed, 
porous, and trabecular rather than spongy. 
The septa are in six systems and four cycles. All are per- 
forate, and have dentate margins. The longest and most con- 
spicuous septa are the quaternaries next the primaries in each 
system. They describe a double curve, and almost meet in front 
of the enclosed secondary. Неге they are connected by a short, 
horizontal, tabula-like process, and, still continuing, each curves 
again outwards towards the corresponding quaternary of the 
adjoining system, and meets it in front of the primary, which is 
thus enclosed by the long quaternaries on either side. The 
remaining quaternaries in each system are short, and, curving 
towards the long ones, join them in front of the still shorter ter- 
tiaries at a third to a half from the wall. The primaries and 
secondaries are stout in comparison with the rest, which are 
slender and sub-equal. 
The corallum is 10 mm. high, and the calice is 9 mm. long and 
m o 5 
7 mm. broad. 
