95 
On the inner surface of the polyp there are very numerous small smooth rodlets with 
bluntly rounded ends. These vary considerably in length, some being so small as to be almost 
spherical, 0.02 X 0.015 mm.; a common size is 0.04X0.015 mm. Similar small smooth rodlets 
also occur in the polyp-stalk and also densely scattered throughout the cortex of the lappets; 
the majority have dimensions similar to those of the polyp, but some attain a greater length, 
being narrow rodlets up to 0.09X0.01 mm. 
In the upper cortex of the branches there are long thorny spindles, some slightly bent, 
up to about 1.5 X 0.08 mm. in size. The basal cortex shows very strong spindles covered with 
compound warts: the largest measured was 1.6 mm. in length with a breadth of 0.15 mm.; a 
common length is 0.9 mm. As the spindles decrease in size, the roughnesses become stronger 
and more prominent; some of the smaller forms show one or several branch-like warty projections 
up to o. 1 mm. long. These finally lead to almost spherical exceedingly rough bodies with a 
diameter of about 0.4 mm. (Fig. b). In addition to these rough warty forms, all of which can 
be considered as derivatives of the spindle type, there are much smaller irregular forms, about 
0.15 mm. in diameter, with several smooth, rather blunt irregular outgrowths. 
In the canal walls lie strong, generally slightly bent spindles with pointed ends; covered 
with rather less numerous prominences, simpler than those of the long spindles of the basal 
rind. Dimensions are 0.8X0.12 mm. A few triradiates and quadriradiates (Fig. a) occur. The 
colour varies from almost white to a very deep cream colour. The largest colony, from Station 60, 
had a total height of 9 cm. with a spread of 11 cm. The stem and branches are rather 
creased and flattened, due obviously to the preservation. The very short sterile stalk has a 
height of 2.2 cm., with a maximum basal diameter of 2 cm. This divides into four almost 
equal branches with diameters of about 1.5 cm.; these almost immediately give rise to the 
lappet-bearing twigs, which may again divide. The colour is a deep cream ; the texture of the 
stem is tough and rather gritty; and the polyparium is distinctly prickly to the touch. 
A smaller colony from the same station, with a height of 7 cm. and a spread of 5.2 cm , 
has two branches. The lappets do not exceed 1.2 cm. 
A very soft and flexible colony from Station 258 agrees in growth, general spiculation 
and the armature of the polyp, but the supporting bundle is in most of the polyps slightly 
more weakly developed, not projecting for more than 0.35 mm., so that the colony is not so 
typically spiny to the touch. 
19. Nephthya sibogae n. sp. 
Stat. 115. Kwandang. Reef. 1 Ex. 
Stat. 301. io° 38'S., I23 0 25'.2E. Reef. 1 Ex. 
We are unable to refer a light brown flexible colony from Station 115 to any previously 
described species of Nephthya. The growth is somewhat tree-like, with a sterile stem which 
branches and rebranches into the bushy polyp-bearing upper portion. The total height is 5.5 cm., 
the length of the stem 2.8 cm. with a maximum diameter of 1.5 cm., and the maximum spread 
of the upper polyp-bearing region is 3.3 cm. 
The lappets vary greatly in size and shape; the smaller ones about 3 mm. high with 
more rounded summits, the larger up to 8 mm. X 4 mm. and conical with rather pointed summits. 
