18 
Colonies of very young polyps from Stations 299 Rotti, 131 Beo, 60 Haingsisi, 19, 56 
Savu and 142 show many small polyps which resemble ordinary Clavularia-like polyps without 
any interlocking Hicksonia stolons yet developed. These, however, may appear in a very young 
individual, as in a young colony from Station 58, Savu, where the polyps ranged from only 
6 — 9 mm.. In one clump a 7 mm. high polyp gave off a stolon 2 mm. from its tip. This stolon 
united with another polyp near the base, and midway another polyp arose from it. 
Comparison of H. viridis and H. kollikeri. 
Both species show the main distinguishing feature of the genus Hicksonia, namely 
connecting stolons forming cross-bridges between the polyps at various levels. From these stolons 
fresh polyps may arise. The bridges are however more regularly short in length in H. viridis , 
so that the polyps remain more or less parallel throughout their length; the length of the 
connecting stolons in H. kollikeri varies to a greater extent, and the whole colony presents a 
less compact, more irregular appearance; the polyps are also considerably shorter. The colour 
in spirit of both species varies from an olive brown to a slightly greener shade. The basal 
stolons of H. kollikeri are more irregular, forming a deeper network than in H. viridis. 
Clavularia viridis 
Hicksonia viridis 
Hicksonia kollikeri 
Maximum length 
10 cm. 
5 cm. 
3.6 cm. 
of Polyp. 
Average breadth 
. . . 
3.5 mm. 
6 mm. 
of top of calyx. 
Pinnules 
. . . 
Two rows of 25 to 30 on each side. 
Two rows of 16 to 20 on each side. 
Spicules of an- 
None 
Numerous minute discs, two, four, 
(, a ) Numerous small rodlets. Average 
thocodia. 
or multi-rayed. Average diameter 
0.03 mm. 
size 0.06 mm. X 0.02 mm. 
( b ) Straight and bent finely warted 
spindles. Some with the ends 
warted or branched. Average size 
0.85 mm. X 0.07 mm. 
Spicules of calyx. 
Long spindles be- 
( a ) Long spindles beset with numer- 
(a) Long delicate spindles with re- 
set with numer- 
ous short simple warts. Maximum 
latively few short simple warts. 
ous small spines 
and tubercles. 
Average size 2.3 
mm. Xo. 14 mm. 
size 2.5 mm. X O.17 mm. 
Maximum length 2 mm.; aver¬ 
age breadth 0.6 mm. 
(b) Large spindles, some with branch¬ 
ed ends, densely beset with 
compound warts which vary 
considerably in size. Maximum 
length from 2.5 mm. to 0.8 mm. 
Average breadth 0.15 mm. 
(c) Irregular, Telestid-like spicules. 
Common length 0.4 mm. 
(b) Stouter spindles densely covered 
with compound warts. Maximum 
length 1.4 mm.; average breadth 
0.13 mm. 
(c) Irregular, Telestid-like spicules; 
0.4 mm. X 0.17 mm. 
