1870. ] DUNCAN—AUSTRALIAN CORALS. 297 
smaller than the cost, 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 colu- 
mella is essential, spongy, and small. 
Height of the corallum 54, inch. Length of calice $$ inch. 
Breadth §, inch. 
Locality. No. 7, 24 miles east of the river Gellibrand. 
Variety. A variety whose corallum is taller, and whose base is 
filled up with sclerenchyma, has larger coste and more distinct 
ornamentation. When worn these fossils present very distinct coste, 
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 coste 
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 cost 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 coste 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 some- 
what 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 51, inch. Breadth of the calice + inch. 
Locality. 14 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 
coste. 
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 cost 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 coste, wavy below, become 
straight above. All are plain. The wall is much thicker at the 
VOI, XXVI.—PART I. ¥ 
