ANTARUTIU BENTHOS
91
The Turridae is a family extremely well represented in deeper water.
It is hardly surprising therefore that this is also one of the important
Antarctic families. Powell (1951, 1965) has illustrated the world
distribution pattern for one of the most noteworthy Antarctic genera,
Aforia. The Eltanin collections contain much more material of this
genus, and also of other deeper water members of this family. Other
turrids almost certainly of deep water origin are the three Antarctic
species of Leucosyrinx, the four of Pleurotomella and one of Pontiothauma. Four endemic Antarctic genera are Belaturricula, Conorbela,
Lorabela and Belalora, the first two confined to the Scotia Arc, the latter
two extending to East Antarctica.
The family Acteonidae supplies an interesting element to the gastropod fauna. The genus Acteon itself has one circum-Antarctic species,
A . antarcticus Thiele. The two other genera occurring in the Antarctic
are Neacteonina with two species and an additional one at Kerguelen,
and Toledonia. This latter genus is widespread in Antarctic (five
species) and Subantarctic (five species) waters. The systematics require
revision and there are probably fewer species than those currently
listed. One species or another supplies a characteristic element to most
molluscan assemblages.
Nudibranchs seem well adapted to the Antarctic-Subantarctic.
Powell (1965) records 58 species arranged in 12 families and 28 genera.
The family Charcotidae with two monotypic genera Charcotia and
Telarma is endemic to the Antarctic as is the genus Notaeolidia with
five species, the genus Azcstrodoris with five species in the Antarctic
and several in the Subantarctic, and the monotypic genera Pseudotritonia and Guyvalvoria. The genus Bathydoris has five endemic Antarctic
species, and there are many other species found exclusively in Antarctic
waters. A more complete treatment of the gastropod fauna of both
Antarctic and Subantarctic waters may be found in Powell (1960, 1965).
5 . Bivalvia (Fig. 12)
A full checklist of Antarctic and Subantarctic bivalves was given in
Powell (1960). The same author (1965) has given a general account of
the Antarctic bivalves. Other recent contributions to the group as a
whole have come from Soot-Ryen (1951), the writer (Dell, 1964b) and
Nicol ( 1966).
Major points of interest only are given below. The family Nuculidae
is one which could be expected to have established itself well in the
Antarctic. To date only one species of Nuculu ( N . notobenthalis Thiele)
has been described from 2 725 m in East Antarctica. The only other
member of the family is Ennucula georgiana Dell endemic to South
91
The Turridae is a family extremely well represented in deeper water.
It is hardly surprising therefore that this is also one of the important
Antarctic families. Powell (1951, 1965) has illustrated the world
distribution pattern for one of the most noteworthy Antarctic genera,
Aforia. The Eltanin collections contain much more material of this
genus, and also of other deeper water members of this family. Other
turrids almost certainly of deep water origin are the three Antarctic
species of Leucosyrinx, the four of Pleurotomella and one of Pontiothauma. Four endemic Antarctic genera are Belaturricula, Conorbela,
Lorabela and Belalora, the first two confined to the Scotia Arc, the latter
two extending to East Antarctica.
The family Acteonidae supplies an interesting element to the gastropod fauna. The genus Acteon itself has one circum-Antarctic species,
A . antarcticus Thiele. The two other genera occurring in the Antarctic
are Neacteonina with two species and an additional one at Kerguelen,
and Toledonia. This latter genus is widespread in Antarctic (five
species) and Subantarctic (five species) waters. The systematics require
revision and there are probably fewer species than those currently
listed. One species or another supplies a characteristic element to most
molluscan assemblages.
Nudibranchs seem well adapted to the Antarctic-Subantarctic.
Powell (1965) records 58 species arranged in 12 families and 28 genera.
The family Charcotidae with two monotypic genera Charcotia and
Telarma is endemic to the Antarctic as is the genus Notaeolidia with
five species, the genus Azcstrodoris with five species in the Antarctic
and several in the Subantarctic, and the monotypic genera Pseudotritonia and Guyvalvoria. The genus Bathydoris has five endemic Antarctic
species, and there are many other species found exclusively in Antarctic
waters. A more complete treatment of the gastropod fauna of both
Antarctic and Subantarctic waters may be found in Powell (1960, 1965).
5 . Bivalvia (Fig. 12)
A full checklist of Antarctic and Subantarctic bivalves was given in
Powell (1960). The same author (1965) has given a general account of
the Antarctic bivalves. Other recent contributions to the group as a
whole have come from Soot-Ryen (1951), the writer (Dell, 1964b) and
Nicol ( 1966).
Major points of interest only are given below. The family Nuculidae
is one which could be expected to have established itself well in the
Antarctic. To date only one species of Nuculu ( N . notobenthalis Thiele)
has been described from 2 725 m in East Antarctica. The only other
member of the family is Ennucula georgiana Dell endemic to South