ANTARCTIC BENTHOS
13
ascidian distribution which is essentially the same as that put forward
by Knox (1960).
1. Antarctic Subregion
A. Continental Province (Antarctic Peninsula to Weddell Sea).
B. South Georgian Province (Bellingshausen Sea, Antarctic
Peninsula to South Georgia).
2. Subantarctic Subregion
A. Magellanic Province (South Georgia to Patagonian Shelf).
B. Kerguelen Province.
C Antipodean Province.
This scheme is a little uncertain in its application since the Antarctic Peninsula occurs in two provinces, as does South Georgia. Kott
is obviously uncertain of the correct location for South Georgia. To
name a province " South Georgia " and then t o exclude South Georgia
from it perhaps indicates that the provincial concept can cause difficulties in itself.
Hedgpeth (1969) proposed a broad scheme as a synthesis of divergent views. This accepted a Subantarctic and an Antarctic Region.
The Antarctic Region essentially fitted within the Antarctic Convergence except where the Kerguelen Subregion of the Subantarctic cuts
across its northern boundary. The Subantarctic Region covers the
southern portion of the area covered by Subantarctic Surface Water.
The Antarctic Subregion was divided into a Continental (or High
Antarctic) Subregion (or Province) with two extensions, and a Scotia
Subregion with South Georgia separated as a distinct District (Fig. 1).
The writer has discussed the validity of the concept of marine
provinces (Dell, 1962), has argued against fine distinctions in the Antarctic Region at our present stage of knowledge (Dell, 1965) and has
shown the Wculties of fitting isolated islands such as Macquarie
into a provincial pattern. He has also (Dell, 1956) shown that in
New Zealand the distribution of the archibenthal molluscan fauna
(200-600 m) bears little relationship to the distribution patterns developed on the shelf. In spite of the number of workers who have discussed marine provinces, there are remarkably few definitions of a province, and most definitions that have been put forward are expressed
in very general terms. A major factor in limiting a province must be
a barrier which will act on all organisms in a similar way causing a large
number of geographic ranges to cease at about the same point. With
marine organisms such a barrier will need to be a wide deep-water gap,
sudden marked changes in temperature or an extensive land mass.
13
ascidian distribution which is essentially the same as that put forward
by Knox (1960).
1. Antarctic Subregion
A. Continental Province (Antarctic Peninsula to Weddell Sea).
B. South Georgian Province (Bellingshausen Sea, Antarctic
Peninsula to South Georgia).
2. Subantarctic Subregion
A. Magellanic Province (South Georgia to Patagonian Shelf).
B. Kerguelen Province.
C Antipodean Province.
This scheme is a little uncertain in its application since the Antarctic Peninsula occurs in two provinces, as does South Georgia. Kott
is obviously uncertain of the correct location for South Georgia. To
name a province " South Georgia " and then t o exclude South Georgia
from it perhaps indicates that the provincial concept can cause difficulties in itself.
Hedgpeth (1969) proposed a broad scheme as a synthesis of divergent views. This accepted a Subantarctic and an Antarctic Region.
The Antarctic Region essentially fitted within the Antarctic Convergence except where the Kerguelen Subregion of the Subantarctic cuts
across its northern boundary. The Subantarctic Region covers the
southern portion of the area covered by Subantarctic Surface Water.
The Antarctic Subregion was divided into a Continental (or High
Antarctic) Subregion (or Province) with two extensions, and a Scotia
Subregion with South Georgia separated as a distinct District (Fig. 1).
The writer has discussed the validity of the concept of marine
provinces (Dell, 1962), has argued against fine distinctions in the Antarctic Region at our present stage of knowledge (Dell, 1965) and has
shown the Wculties of fitting isolated islands such as Macquarie
into a provincial pattern. He has also (Dell, 1956) shown that in
New Zealand the distribution of the archibenthal molluscan fauna
(200-600 m) bears little relationship to the distribution patterns developed on the shelf. In spite of the number of workers who have discussed marine provinces, there are remarkably few definitions of a province, and most definitions that have been put forward are expressed
in very general terms. A major factor in limiting a province must be
a barrier which will act on all organisms in a similar way causing a large
number of geographic ranges to cease at about the same point. With
marine organisms such a barrier will need to be a wide deep-water gap,
sudden marked changes in temperature or an extensive land mass.