a. Cells distichous.
1. S. elongata, Lamouroux.
Habitat: Swan Island, Banks Strait, thrown on the beach. Port Dalrymple, on stones at low water. (Also New Zealand.)
2. S. divaricata, n. sp.
Cells urceolate-subtubular, or very little contracted towards the mouth, often adnate to the rachis nearly their whole length; mouth looking upwards, with three large acute teeth, two lateral, and one rather longer than the others, and slightly recurved, above. Ovicells ---- ?
Habitat: Bass Strait, 45 fathoms, dead shells.
Colour dirty yellowish white; polypidom branched, from a common stem; branches irregular (?) straggling, pinnate and bipinnate, pinnae and pinnules divaricate at rightangles, alternate; rachis flexuose, or with an angle at the origin of each pinna. The cells are placed at wide distances apart; small and adnate very nearly to the top. The mouth circular, with three large teeth, the one above frequently obscured by adventitious substances, very acute, ascending, and a little recurved.
Sertul. gayi. (Lamouroux. Exp. page 12 plate 66 figure 89 has four teeth.)
This species occurs also on the south coast of Patagonia, and the Straits of Magellan; in the latter locality, however, the habit is much more robust.
3. S. crisioides, Lamouroux. (Dynamena.)