Leptosynapta

Verril, 1867

32 species

Not having the shape of a narrow handle, sharply set off from the outer part of the plate. (Mortensen, 1927 adds this)

Tentacles 10-12, usually pinnate. Digits, few, 1-9 on each side, (in L. minuta, Becher says digits wanting). Sensory cups usually present on the tentacles and eye spots are wanting. Radial pieces of the calcareous ring perforated for the nerves. A cartilaginous ring wanting. Polian vesicles few. The stone canal is single and unbranched. Ciliated funnels are always present (in minuta there is but a single one), and of quite varying shape. The calcareous deposits are often slightly different in the two ends of the body, those from the posterior end being larger. Anchor plates with seven large toothed holes. A well defined bridge is wanting. (Heding, 1928)

pinnate tentacles 10-13 usually with 4 or more digits on each side (rarely 3 or only 2 or none). Cartilaginous ring wanting. Polian vesicle single rarely more than one. Stone canal single unbranched. Sense organs never in the form of pigment eyes, but as minute cups probably olfactory, on inner surface of stalk of tentacles. Stock of anchors finely toothed but not branched. Arms usually upward or outwardly projecting teeth on outer edge, vertex smooth. Basal part of anchor plate gradually narrowing, with large central hole, surrounded by 6 other large holes, usually more or less dentate and without any arched bow across the outer surface. (Deichmann, 1930)