856 THOMSON AND RITCHIE ON THE ALCYONARIANS 
variable number of polyps in a whorl is of greater importance, but it probably means 
nothing more than a greater vigour of growth. 
The figure in the Challenger Report shows the whorls too far apart, as the text 
points out; we have therefore given a supplementary figure. 
Locality.—Burdwood Bank, lat. 54° 25’ S., long. 57° 32’ W.; 52 fathoms. Surface 
temperature 40°8°, December 1, 1903. 
Family MURICEID/AL. 
Paramuricea robusta, n. sp., Pl. I. fig. 6; Pl. IL figs. 2 and 7. 
A strong upright colony of a light brown colour, expanded for the most part in 
one plane, 27°5 cm. in maximum height by 14 cm. in maximum breadth. Not far 
from the base, which is expanded to 2 cm. and soon narrows to 1 cm., a strong 
side-branch is given off with a diameter of 6 mm., and this, like the main stem, bears 
strong offshoots from which smaller, usually simple, branches arise. The branching 
is very irregular, but anastomosis is rare, being represented in one of the specimens by 
only two instances, one of which shows the junction of an apparently broken branch of 
the first degree with the main stem. In another specimen, 18 em. by 12 cm., there is no 
anastomosis. Towards the base of the colony the main stem is distinctly flattened, 9°5 
by 8 mm., immediately above the basal thickening. 
The axis is horny, non-calcareous, fibrous, and of a brownish colour. It narrows 
from about 6 mm. near the base to 1 mm. near the tips of the branches. 
The ccenenchyma is relatively thin (0°5 mm.) and somewhat translucent, allowing 
the brownish axis to shine faintly through. Its surface is rough, owing to the abundance 
of large colourless spicules which cover it. Some of these spicules project from the 
tops of the verrucze as crowns of spines. 
The yellowish verruce are cylindrical with a slightly conical summit, 1°5 mm. in 
height by 1 mm. in diameter, and arise perpendicularly from all sides of the main stem 
and its branches. They are closely set, without any regular interval between them. 
Four or five are always grouped at the tip of a branch, giving it a knobbed 
appearance. 
The polyps are wholly retracted, and an operculum of 8 parts, each composed of 
about 5 spicules resting on the bases of the tentacles, closes over the aperture. Round 
the top of the verruca a few rows of spicules are arranged horizontally, and on this 
support the bases of the opercular covering rest. 
Various types of spicules characterise the species. Most characteristic are the large 
tuberculate clubs whose ‘ handles’ form the spiny crowns of the verrucze, while the much 
divided root-like ‘ heads’ are embedded in the coenenchyma. ‘There are also simpler clubs 
with heads covered with tubercles and spiny processes. Curved spindles are common, 
some knobbed and thickened, with comparatively large projecting processes and smaller 
