16 
Proceedings of the Royal Society of Edinburgh. [Sess. 
thecse ; where secondary and subsequent individuals are present they are 
free, and may reach far beyond their own internode. 
The dimensions of the hydrothecse are greater than those of the type 
specimen, judging from Billard’s measurement. 
Several of the extraordinary aggregates of gonangia-bearing branches 
occur. They resemble the “ coppinia ” masses which occur in the Lafoeidse 
only in a very general way ; for here is none of the aggregating of gonangia 
Fig. 2. — Part of branch of Ophiodes arboreus Fig. 3. — Part of branch of Ophiodes arboreus 
from Cape Royds. x 25. from Cape Royds, showing free hydro- 
thecse. x 25. 
into closely compressed, compact, unified groups radiating from the support- 
ing stem. The aggregate is of a more casual type, the essence of which is 
that the stolon-like branches, upon which the gonangia are grouped in pairs, 
arise from a limited portion of the stem, and ramify to such an extent that 
an inextricable tangle arises. The hook-like tube at the distal end of a 
o 
gonangium is usually even longer and more curved than Hickson and 
Gravely represent in their figure. All the gonangia observed contained 
female reproductive products. 
There has just come to my notice the description of a species from North- 
