Dentitheca hertwigi

Stem long (30 cm), flexuous, branched, strongly fascicled near base.

Hydrocladia with 12-15 hydrothecae, hydrocladial internodes with 5-7 strong septal ridges.

Hydrothecae long, adnate, abcauline wall curving over distally towards hydrocladium; an indistinct intrathecal fold sometimes present about halfway along thecal wall. Margin with 2 broad bluntly pointed lateral lobes, usually of the same size and shape, occasionally 1 lobe much more prominent than the other.

Western Pacific, including southern and western Australia.

Subtidal, free growing on sandy substrates.