border supporting 2 to 4 long incurved spines; 2
to 3 other long curved submarginal spines behind or above the opening,
none below it in front--a solitary spine on the back a short way down the
cell. Avicularia very long, trumpet-shaped, arising on the back of the
cell.

Habitat: Bass Strait, 45 fathoms.

This species is at once recognisable by the remarkable form and unusual
position of the avicularium, and also by the peculiar digitiform
spiniferous process on the outer side of the opening.

2. B. gracilis, n. sp.

Cells elongated, slender, opening round or suboval, looking obliquely
forwards and upwards; three marginal (sometimes slightly submarginal)
spines above and behind the opening, and two much longer curved hair-like
spines arising from the anterior and lower edge of the opening. Ovicells
globose, subpedunculate, attached to the upper and inner part of the
margin of the opening. Avicularia small, like birds' heads.

Habitat: Bass Strait.

A delicate slender species, not unlike B. ciliata or avicularis in habit.
The two long spines arising from the anterior edge of the opening suffice
to distinguish it from the former of these two species.

3. B. grandis, n. sp.

Cells much elongated outwards, horizontal or projecting portion oblong,
rounded at the extremity; 2 to 5 long curved submarginal spines,
externally a single dorsal spine about halfway down the cell; opening
oval, narrower outwards; very oblique mouth at the outer end. Avicularia
---- ?

Habitat: Bass Strait, 45 fathoms.

Quite distinct from B. ciliata not only in its size, which is nearly
three times as great, but in the form of the cell and the opening. The
number of spines varies very much, and two or three of them, not
unfrequently, arise from a common projecting process or base.

4. B. johnstoniae.

Cells obliquely truncated above with a short spine on the outer angle;
opening large, suboval, with an obtuse angle outwardly; margin slightly
thickened, wholly unarmed.

Habitat: Off Cumberland Islands, 27 fathoms, fine grey mud.

Of a light grey colour: grows in large loose tufts, composed of long
forked ascending branches. It is a very peculiar species, and some
difficulty has been found in finding it a place. In the opening of the
mouth, and the external short spine, it is a Cellaria; and in the colour
and want of distinct articulation, it approaches Acamarchis; whilst in
the form of the cell, and their mode of mutual connection, i