The adjacent sporangia also become cut off by septa, and the investing membrane, when mature, opens: it a beak-like prolongation, thus permitting the inclosed densely congregated green granules to be penetrated by the antherozoids which swarm from the antheridium at the same time.

Fertile pinnæ on separate fronds, which are contracted and covered with brown sporangia.

Fertile frond one to three pinnate, the contracted divisions bearing a double row of sessile, naked, globular sporangia, opening transversely into two valves.

Mature sporangia varying from dark yellow-brown to almost black.

Fertile frond one to three pinnate, the contracted divisions bearing a double row of sessile, naked, globular sporangia, opening transversely into two valves.