In Antarctic and sub-Antarctic seas, the genus Liljeborgia
has been recorded from 4 to 4385 m. The occurrence of
12 valid previously named species is con?rmed south of
40°S (Tasmania and New Zealand excluded): L. chevreuxi
SCHELLENBERG, 1931, L. consanguinea STEBBING,
1888, L. eurycradus THURSTON, 1974, L. georgiana
SCHELLENBERG, 1931, L. georgiensis K.H. BARNARD,
1932, L. kerguelensis BELLAN-SANTINI & LEDOYER,
1974, L. longicornis (SCHELLENBERG, 1931), L. macrodon
SCHELLENBERG, 1931, L. octodentata SCHELLENBERG, 1931,
L. pseudomacronyx BELLAN-SANTINI & LEDOYER, 1987, L.
quadridentata SCHELLENBERG, 1931 and L. quinquendentata
SCHELLENBERG, 1931. All these species are re-described in
detail, wherever possible after the types. In addition, 11 new
Antarctic and sub-Antarctic species (6 shelf and 5 deep-sea
species) are described: L. abyssotypica n. sp., L. bythiana n.
sp., L. cnephatis n. sp., L. cryptothrix n. sp., L. homospora n.
sp., L. nesiotica n. sp., L. permacra n. sp., L. polydeuces n. sp.,
L. prionota n. sp., L. rauscherti n. sp. and L. semperhiemalis
n. sp. Two additional species (Liljeborgia sp. 1 and sp. 2)
are characterized but not named, due to the inadequate
condition of the available material. It is demonstrated that
L. falklandica K.H. BARNARD, 1932 is a junior synonym
of L. octodentata SCHELLENBERG, 1931. The Antarctic and
sub-Antarctic records of L. dubia (HASWELL, 1879), and
the sub-Antarctic record of L. proxima CHEVREUX, 1907
are not accepted because the types of these species originate
respectively from warm-temperate and tropical seas, and
such species from warmer climates are unlikely to occur in
the frigid waters of the Southern Ocean. Several species have
a very restricted distribution (e.g. insular endemism) and such
species are probably very vulnerable to major environmental
alterations. All Antarctic and sub-Antarctic Liljeborgia can
be divided into two morphologically homogeneous groups
of species: a group without setae on the outer distal border
of the ?rst article of the palp of the maxilliped and with only
one (distal) spine on the dorsomedial border of the peduncle
of the ?rst uropod, and a group with dorsal setae on the outer
distal border of the ?rst article of the palp of the maxilliped
and with several spines on the dorsomedial border of the
peduncle of the ?rst uropod. These two groups, which are
also characterized by other less constant characters, appear
widely distributed across the world oceans.