2 
A new Deltocyathus, represented in the South Australian 
dredgings by numerous examples, is the recent analogue of an 
undescribed fossil form which occurs, more or less abundantly, in 
certain outcrops of the Victorian and Tasmanian tertiaries. 
My examination of the corals referred to in this paper has 
been greatly facilitated by the loan of the types of some recent 
species described by Tenison Woods. These are deposited in 
the Macleay Museum, Sydney, and I sincerely thank Professors 
David and Haswell (Trustees), and Mr. Masters (Curator), of the 
Museum, for kindly placing them at my service. I am also 
under obligations to Mr. F. Chapman for photographs of Woods’ 
types, as well as for information concerning the organisms to 
which some of the coralla are attached. 
In classifying the species account is only taken of families and 
genera, and the order followed is that given by Duncan in his 
* Revision." 
TURBINOLIDA, 
Genus Внілотвосноѕ, Milne Edwards and Haime. 
Rhizotrochus radiatus, spec. mov. РІ. i., figs. la, b. 
The corallum is compressed and flabelliform. The radicles 
form varying angles with the wall, are six in number, rarely 
more or less, and surround the central pedicellate base. In 
young examples they are hollow tubes, which open freely into 
the interseptal chambers. With age, however, the orifices are 
much diminished from internal thickening of the tube walls. 
Of the numerous specimens collected the majority have become 
detached, but some are still firmly fixed by their long, radiating 
roots to calcareous algæ or fragments of bivalve shells. 
The calice is deep and elliptical, with the major and minor axes 
in the ratio of 100 to 63. Тһе septa are thin, non-exsert, finely 
denticulate, and studded with minute, sharply pointed granules. 
Hexameral arrangement of the septa is evident in very young 
examples, with the primaries, secondaries, and tertiaries normally 
developed, the latter being short. As the coral grows, some 
tertiaries lengthen, and other orders develop, until in the adult 
there are 20 long septa and apparently as many systems with 
three cycles in each. The total number of septa in the large 
example figured is 80, viz., 20 long, 20 of medium size, and 40 
very short and thin. The columella is formed of foliated, 
fascicular outgrowths from the central ends of the principal septa. 
The wall is very thin, especially at the margin, and when not 
covered, as is often the case, by incrusting polyzoa, serpulæ, etc., 
almost translucent. Broad Hat coste corresponding to the 
septa are distinct in most examples, beneath a delicate epitheca. 
