b. Cells (on the branches) secund, contiguous.
10. S. divergens, Lamouroux.
Cells urceolate, much contracted towards the mouth; upper half free, divergent, projecting laterally almost horizontally; mouth small elliptical, with the long axis looking directly outwards; two lateral teeth. Ovicell smooth, rounded, ovoid; oral margin not elevated.
Habitat: Swan Island, Banks Strait.
Colour light yellowish: parasitic upon a fucus. Height from 1/4 to 1/2 inch; simply pinnate, branches distant, regularly alternate. The stem is divided into internodes, from each of which arises a single branch. The cells on the stem are alternate.
b. Cells secund.
11. S. trigonostoma, n. sp.
Cells ovoid, gibbous, much contracted towards the mouth. Very small portion free, projecting forwards and outwards. Mouth looking outwards and forwards, triangular, with a short blunt tooth on the external angle. Ovicell ---- ?
Habitat: Prince of Wales Channel, Torres Strait, 9 fathoms.
Colour very light yellowish. Polypidom simply pinnate, about two inches high: longest pinnae about half an inch. Cells small adnate, projecting suddenly at top, and much contracted at the mouth. The mouth is of a triangular form, the longest side of the triangle being below. The cells are placed in pairs, but one is always a little higher than the other (subalternate) and one pair is placed on each internode on the pinnae. The stem is also indistinctly divided into internodes, from each of which a single pinna is given off alternately on opposite sides, and besides the pinnae there are three cells on each internode, two on the side from which the pinna springs, and on the opposite side alternate in position to the other two.