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 .