sets, at some distance apart.

1. P. hexodon, n. sp.

Cells in sets of six--three on each side; a single axillary cell in each
dichotomous division of the polypidom. Ovicell pedunculate ovoid, adnate
to the rachis, with a lateral opening.

Habitat: Off Cumberland Isles, 27 fathoms.

As this differs in the number of cells in each set, as well as in the
form of the cells, and in the form and position of the ovicell, it
appears irreconcilable with Lamouroux' P. quadridentata. According to the
figure given of the latter the ovicell is not adnate, and is spirally
grooved.

3. PLUMULARIA, Lamarck.

a. Angiocarpeae--ovicells enclosed in siliquose, costate receptacles.

1. P. huxleyi, n. sp.

Plumularia--Huxley, Philosophical Transactions Part 2 1849 page 427 plate
39 figures 43 and 45.

Cells cup-shaped, shallow; mouth nearly vertical, subquadrangular, margin
subcrenate, plicate; with a small acute central denticle in front, and a
wide shallow notch behind. Rostrum twice as long as the cell, arising
from the rachis by a broad ventricose base, adnate the whole length of
the cell, narrow upwards and slightly expanded again at the summit;
lateral processes very short and wide, canalicular adnate. Costae of
ovarian receptacle numerous, each with a single branch near the bottom,
and beset with small cup-like processes, and not connected by a membrane.

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

Colour yellowish white. Polypidom about 6 inches high, rising with a
single flexuose stem, which is naked at bottom, and afterwards gives off
alternate branches, bifariously disposed at each angular flexure.
Branches simple, 2 to 3 inches long; pinnules about 1/4 inch. The
construction of the ovarian receptacle in the present section of the
genus Plumularia is well exemplified in this species, owing to the
comparative simplicity of the elements of which it is composed.

2. P. hians, n. sp.

Cell cup-shaped, deep, cylindrical; mouth nearly vertical; margin with
three teeth on each side, the middle one the longest, acute, much
expanded, the other more rounded; a wide notch posteriorly. Rostrum,
arising from the rachis, as long as the cell, slender, tubular, adnate;
lateral processes very small, ovarian receptacles ---- ?

Habitat: Prince of Wales Channel, Torres Strait, in 9 fathoms.

Colour bright brown, rachis shining, very dark brown; polypidom about six
inches high, simply pinnulate, pinnu