Paracolochirus, Pawson, David L., Pawson, Doris J. & King, Rachael A., 2010

Pawson, David L., Pawson, Doris J. & King, Rachael A., 2010, A taxonomic guide to the Echinodermata of the South Atlantic Bight, USA: 1. Sea cucumbers (Echinodermata: Holothuroidea), Zootaxa 2449, pp. 1-48 : 18

Paracolochirus , new genus

Diagnosis. Tentacles ten, of equal size. Ventral feet in approximately 3 rows; dorsally, scattered papillae. Body wall thick, fleshy. Calcareous ring simple, with undulating posterior margin. Ossicles in body wall fourholed plates with low knobs. Tentacles with numerous c-shaped rods of varying size, usually with terminal perforations. Feet lack endplates.

Type species: Pseudocolochirus mysticus Deichmann, 1930 , by monotypy.

Type specimen: Catalogue No. 189, Museum of Comparative Zoology, Harvard University.

Remarks. Deichmann (1930) referred her new species mysticus to the genus Pseudocolochirus “ gen. nov. ” with the type species Colochirus violaceus Théel (1886a) . Deichmann noted that Pearson had proposed the genus-name Pseudocolochirus in a letter to Theodore Mortensen, but had never published it. Clark (1938) confirmed that Pearson (1910) had indeed published the new genus name Pseudocolochirus , with violaceus Théel as the type species by monotypy. At present, Pseudocolochirus comprises two species (see Rowe and Gates, 1995; Thandar and Samyn, 2004), with a broad Indo-West-Pacific distribution in depths of 0– 13 m. The western Atlantic mysticus Deichmann has knobbed four-holed buttons about 100 µm long in the body wall, and almost exclusively c-shaped rods up to 500 µm long in the tentacles. In contrast, P. violaceus has thick and smooth buttons and plates up to 500 µm long, with several partially occluded holes, in the body wall, and in the tentacles elongate perforated plates up to 400 µm long, and much smaller rods of various shapes. Given these differences, and the distribution ranges of the species, it is considered best to erect a new genus to accommodate the species mysticus . This matter will be discussed more fully elsewhere (Pawson and Pawson, in preparation).