1870.] DUNCAN AUSTRALIAN CORALS. 297
smaller than the costae, and rather exsert, but soon become thin,
granular laterally and rather wavy in their course ; they are long,
wide apart, and unequal ; those of the higher orders are long, and
turned towards the tertiary near the columella; there are four
cycles of septa, in six systems. The pali are slightly broader than
the septal ends, and are long and granular. They are before
all the septa except those of the fourth and fifth orders. The columella
is essential, spongy, and small.
Height of the corallum 4/10 inch. Length of calice 10/30 inch. Breadth 8/30 inch.
Locality. No. 7, 2-1/4 miles east of the river Gellibrand.
Variety. A variety whose corallum is taller, and whose base is filled up with sclerenchyma, has larger costae and more distinct ornamentation. When worn these fossils present very distinct costae, with an uneven free surface. They occur in a kind of dark shale, and are found in numbers together.
4. Deltocyathus italicus, var. australiensis. Plate XIX. fig. 4.
The corallum is in the shape of a very short cone. The costae are very distinct from the base to the calicular margin ; they are nearly equal in breadth ; but there are twelve which are longer than the others, and straight. Those next in size bifurcate, and the smallest are placed between the costae resulting from the bifurcation. All are rounded, intensely and distinctly granular externally and laterally, and separated by deep intercostal spaces. The calice is circular in outline, rather convex ; and the costae run into septa without the wall being seen. The septa are unequal in length, but very equal in thickness ; they are simply granular, stout, and somewhat arched. There are four cycles, in six systems. The pali are very distinct, granular, and broad ; they are placed before the secondary and tertiary cycles. Those before the secondary septa are nearest the columella ; and those before the tertiary do not pass in a right line to the columella, but to the secondary pali. The columella is papillary.
Height of the corallum 1/10 inch. Breadth of the calice 1/5 inch.
Locality. 1-1/2 mile west of Cape Otway.
The typical Deltocyathus is found at Tortona, in a miocene deposit ; it is very closely allied to the Australian form, which has granular costae.
5. Sphenotrochus australis, Duncan. Plate XIX. fig. 5.
The coral is very compressed, especially inferiorly, where, on either side of the centre of the base, a process passes downwards, giving it a " fishtail " appearance. At the calice the compression is less, but the great axis is at least twice the length of the smaller. The coral is longer than broad. The costae are broad, somewhat wavy, and separated by well-marked lines : those of the inferior appendages arise from the extremities of the processes, and pass upwards and inwards ; and the lateral costae, wavy below, become straight above. All are plain. The wall is much thicker at the
vol,. xxvi. — part i. y
