61 
direct continuations of the costæ, the only visible boundary 
between them being the under surface of the corallum. 
They are in six equally developed systems, with four 
cycles, and show the delta-like combinations characteristic 
of the genus. In the several deltas, large, stout, and much 
raised pali are placed before the union of the short 
quaternaries with the tertiaries, a deep notch in all 
three septa marking the point of junction. At 
lts outer end each palus consists of three separate 
Processes, of which the central one is longer, higher, 
and more arched than the others. The solid portions of 
these pali taper somewhat, converge in each system, and 
then unite laterally with the enclosed secondary septum. 
The other pali reach the columella and are much smaller, 
especially the primaries, which are slender, much like the 
septa themselves, and united to them by thin, sunken pro- 
cesses; the secondaries are irregular in shape, more central 
than the tertiaries, and less conspicuous in the calice. All 
the septa and pali are similarly covered on their sides by 
closely set rows of stout granules. 
Diameter, 10 mm.; maximum height (to summit of pali), 
mm. 
Locality, etc.—Rare in the Spring Creek section; five 
examples. 
This species is at once distinguished from other Delto- 
cyathi of the Australian tertiaries by its flattened outline, 
coarsely granulated coste, and large tertiary pali. 
Deltocyathus fontinalis, spec. nov. Pl. xxiii, figs. За, b. 
The coralla are generally discoid in outline, rarely shortly 
cylindrical. They vary also in size. The base has a rounded 
margin, and may be fiat, barely convex, or hollowed out 
centrally. A scar of former attachment is occasionally pre- 
sent. The coste are finely granular, radiate on the base, 
and perpendicular, or nearly so, from the basal margin to 
the border of the calice, when they again curve round, and 
are continued as septa. They are equal, broad, and in six 
systems with four cycles. In examples with no basal scar 
the primaries and secondaries are traceable to the centre; 
the quaternaries fuse together near the centre and enclose 
the shorter tertiaries. The wall is thin, low, deeply seated, 
and rarely visible in the narrow interspaces of the coste. 
The calice is circular, slightly convex, or almost flat, with 
a shallow central fossa. The septa are unequal in length. 
Stout, and very granular. The pali are also granular, and 
are placed before the first three orders of septa. Those Le. 
fore the tertiary septa are the largest and converge towards 
