REPORT ON CORALS—DEEP-SEA MADREPORARIA. 207 
are derived from the main branches next the primary septa, whilst only two are derived 
from those next the secondaries. A distinct deltoid arrangement is observable in the 
disposition of costal trabecule. The outer trabeculee next the primary septa are straight 
or nearly so for their entire length, running parallel to and close beside the primary 
septa; all their branchings appear to occur on their sides lying next the secondaries. 
Thus each system is complete in itself, and more or less separate both above and below 
in the corallum ; the crossings of the costal trabecula under the septa, necessitated by 
their different mode of branching, are confined to the interior of each system. So regular 
are the bifurcations of the septa that I am at a loss to designate the quinary, quaternary, 
and tertiary septa in each system as such, the terms would seem hardly to apply. The 
costal trabeculz appear to grow first in the development of the coral, as is shown by the 
projection of them at the margin, without corresponding septa developed as yet above them. 
The animal of the present species is flat and discoid, and of very small elevation 
except around the mouth, which is elevated at its margin above the disc (Pl. XVI. 
fig. 4). The tentacles are elongate, conical in form, with large rounded knobs at their 
tips. There are six small but long tentacles placed upon the disc at about one-third of 
the distance from the margin to the centre, and over the primary septa. At the margin 
of the disc there are tentacles of two sizes, larger and smaller, which alternate with one 
another, the smaller being placed at a slightly higher level on the edge of the coral than 
the larger, which lie in the same place as the disc itself. There are twelve marginal 
tentacles, six large and six small, in each system. ‘The tentacles correspond in position 
to the intervals between the marginal spines that is to the lmes of the septa. The 
larger tentacles correspond to the intervals between the marginal spines which are least 
deeply indented. The tentacles are probably absolutely non-retractile. The entire dise 
of the animal to its very margin, which coincides with the tips of the marginal spines, 
was coloured, in a fresh specimen examined, dark madder; the mouth was of a light 
orange colour; the tentacles transparent and colourless, with opaque white tips. The 
thread cells in the knobs of the tentacles were found to be of a similar form to those 
occurring in the tentacles of Corallimorphus profundus (Moseley) of the very elongate 
cylindrical form." 
Extreme diameter of the fresh animal between the tips of the tentacles, 38 mm. 
Extreme diameter of the corallum, 25 mm. Extreme height from the centre of the base 
to the tips of the spines of the septa, 2 mm. 
Four specimens in all of this coral were obtained on three occasions in deep water 
in the Southern Atlantic and South Indian Oceans. 
Station 147, in the Southern Indian Ocean, 80 miles west of Hog Island, Crozette 
Islands. Lat. 46° 16’ 8., long. 48° 27’ E. 1600 fathoms. 
1 H. N. Moseley, On New Forms of Actiniaria Dredged in the Deep Sea, Trans. Linn. Soc., 2 ser., Zoology, vol. i. 
p- 300. 
