Habitat:  Swan Island, Banks Strait, thrown on the beach.

Colour bright brown; polypidom pinnate; the stems arising from creeping radical tubes, very thickly intertwined around a long slender body.  The stems are from one to four inches long, the pinnae about 1/4 to 1/2 inch, alternate.  The rachis of the stem is divided into distinct internodes, from each of which are given off two pinnae, and upon which are also placed usually six cells, three on either side.  The pinnae are also divided, but less distinctly, into internodes of various lengths.  The pairs of cells on the pinnae are all secund, and in contact with each other at their bases, though widely divergent above.

15.  S. tridentata, n. sp.

Cells urceolate, ventricose below, contracted towards the mouth.  Mouth looking forwards and outwards, circular, with three acute teeth, two lateral, longer than the third, which is above.

Habitat:  Bass Strait, 45 fathoms.

Colour yellowish white.  Polypidom simply pinnate, about 2 1/2 inches high; pinnae in the middle 3/4 of an inch.  The cells are ventricose below, and almost flask-shaped.  The two lateral teeth are long, acute, and slightly everted; the upper third tooth is sharp, but not near as long as the others; the border of the mouth is as it were excavated below, so that the mouth is as nearly as possible vertical.  Contrary to what is the case in S. divergens, but exactly as is represented in Savigny’s figures of the so-called S. disticha (Egypt plate 14 figures 2 and 3); and S. distans (Egypt plate 14 figures 1 and 3) the lateral teeth are sloped or bevelled off from below upwards, and not from above downwards, as in S. divergens (Mihi).

2.  Pasythea, Lamouroux.

Cells in distinct 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.