A supplement to the fauna of holothurians of the family cucumariidae (Echinodermata: Holothuroidea) from the Sea of Okhotsk

This work studies a new genus Apseudocnus and three new holothurian species: Apseudocnus albus, Cucumaria obscura, and C. fusiformis, found in samplings of the 27th and 29th cruises of the research vessel Akademik Oparin to western and southeastern areas of the Okhotsk Sea. The new species distinctly differs from other known cucumariids in the structure of spicules of the body walls, tentacles, and the circumpharyngeal calcareous ring. Descriptions of the new taxa are presented with diagnoses and figures.