Acryptolaria gracilis (Allman, 1888)

Most of the polysiphonic tubes run more or less parallel up the stem but with some minor contortions. The hydrothecae are thick-walled and deeply immersed in the perisarc and can only be properly seen in the monosiphonic region of the branches. Although most hydrothecal margins are damaged and many are completely immersed in the branch, some show unusual annular thickenings resulting from thin fascicular tubes running around the margin.