Polyplectana

Clark, 1907

9 species

Tentacles pinnate 25, sometimes 26 or 27; individuals are often found with 24 or fewer. Digits numerous, 15-40 on each side. Cartilaginous ring present. Polian vesicles very numerous, 20 or more. Stone canal single. Stock of anchors not branched, though finely toothed; arms smooth, but vertex with some minute knobs. Anchor plates with large central hole, surrounded by 6 other large holes, all dentate except for the most posterior, which may be smooth, and with two large and several small entire holes at the narrower posterior end, where a well formed and distinctly arched bow crosses outer surface of plate. Miliary granules present, but tentacles without supporting rods. (Clark, 1907)

Differs from Synaptula only on the number of tentacles and the size of the miliary granules. In Polyplectana they are branched and curved rods. (Heding, 1928)