Achiridota Clark, 1908

O’Loughlin, P. Mark & VandenSpiegel, Didier, 2010, A revision of Antarctic and some Indo-Pacific apodid sea cucumbers (Echinodermata: Holothuroidea: Apodida), Memoirs of Museum Victoria 67, pp. 61-95 : 67

Achiridota Clark, 1908

Achiridota H. L. Clark, 1908: 126 .— Heding, 1935: 16.— Smirnov,

1998: 521.

Diagnosis (of type species, following Fisher 1907, and Smirnov 1998). Tentacles 12, trunk stout, digits small; 6–8 pairs of digits per tentacle, increasing in size distally, distal digits paired not single; calcareous ring well developed, radial and interradial plates with anterior projection/tooth, straight posterior margin; lacking ossicles; single polian vesicle; madreporite at anterior edge of dorsal mesentery, close to ring canal; gonad tufts with central trunk and simple or dichotomous branches.

Type species. Anapta inermis Fisher, 1907 (Hawaiian Is, 466– 772 m).

Other species. Achiridota profunda Heding, 1935 ( N Atlantic, 2700 m); Achiridota smirnovi sp. nov. (E Antarctica, 518–788 m).

Remarks. Achiridota Clark, 1908 was initially assigned to Chiridotidae , but was subsequently assigned to Myriotrochidae by Smirnov (1998) on the basis of having: large anterior teeth on the plates of the calcareous ring; single polian vesicle; madreporite close to ring canal. Although Heding (1935) referred two new species to Achiridota he argued convincingly that one of his species ( Achiridota ingolfi Heding, 1935 ) was more Chiridota - like because of the form of the calcareous ring and presence of 11 polian vesicles. We judge that Achiridota ingolfi belongs more appropriately in Chiridota Eschscholtz, 1829 .