The Holothurian Fauna of Cook Strait, New Zealand
Diagnosis: Calcareous deposits in the form of six-spoked wheels; sigmoid or C-shaped rods may be present. Tentacles with short stalks, becoming widened distally, where they bear 3–10 digits on each side. The digit-bearing portion forms a disc and the tentacles are therefore peltato-digitate.
Clark (1907) noted that the sexes are separate in many species. Sigmoid rods have each end curved in opposite directions, often in planes at right angles to each other. Rods in which the ends are curved inward towards each other are C-shaped or bracket-shaped.
This family comprises mainly small holothurians. The group is world-wide, and most of the species live in the littoral zone. Three genera and six species of Chiridotidae are known from New Zealand, of which three species are found in the Cook Strait region.page 7
|1||(2)||Calcareous deposits absent from the body wall||Kolostoneura Becher, 1909|
|2||(1)||Wheels present, scattered or arranged into loose heaps, or sometimes so scattered as to be easily overlooked. Sigmoid rods also present in numbers||Trochodota Ludwig, 1892|