Bactromesus antarcticus Kussakin, 1982: 95.
Etymology. In honour of Oleg Kussakin, who first described this species.
Remarks. Bactromesus antarcticus Kussakin, 1982 was described from specimens collected from the South Shetland Islands. Kussakin (1988) synonymised Bactromesus Wolff, 1962 with Ischnomesus Richardson, 1908, thus transferring his and the two original species of Bactromesus to Ischnomesus. However, Schultz (1979) had already described Ischnomesus antarcticus Schultz, 1979 from west of the Anvers Island, and thus I. antarcticus (Kussakin, 1982) is a junior homonym. A replacement name, Ischnomesus kussakini nom. nov. is here proposed. I. kussakini nom. nov. can be distinguished from I. antarcticus by the absence of dorsal and lateral spines on the cephalon and body.