NEW BENTHOPELAGIC THARYBIDS (COPEPODA, CALANOIDA) FROM THE DEEP NORTH-ATLANTIC

A new genus is proposed to accommodate Rythabis atlantica gen. et sp. n., collected by means of a MOCNESS opening-closing net from 2840 m de pth ca 20 m above the seabed in the North Atlantic south of Iceland. T he new genus is placed in the family Tharybidae and appears to be clos ely related to Tharybis, but differs in several characters of prosome, urosome and appendages. In addition, two members of the genus Tharybi s, T. angularis sp. n. and T. crenata sp. n., are described and illust rated from the same plankton haul on the basis of adult females. Xanth ocalamus groenlandicus TUPITZKY, 1982 is transferred to Tharybis; this brings the number of species attributable to the genus to 13.