TRANSACTIONS OF SECTION D. 413 
outlet valleys, I do not think that we should ascribe their whole excavation to 
the work of cwm glaciers. I do not know whether Mr. Taylor would press for 
that. These main valleys seem partly tectonic, partly glacial, and very possibly, 
in their earliest inception, partly fluviatile. 
Next, in regard to the Great Ice Barrier, the Ross Barrier—the huge 
equilateral triangle with sides about five hundred miles in length—is fed by a 
very large number of glaciers. It has been said by some that it is merely sea- 
ice thickened by additions of annual snows going on for thousands of years, 
until at last a thick mass results of sea-ice at the base, while the snows and 
névés of a thousand or more years form the remainder of its bulk. I would 
point out that if that were the case, we would surely expect the Ross Barrier 
to have a pretty even cliff facing the ocean. But we do not find that condition 
at all; we find it is very variable in height—from twenty feet in some places to 
a hundred and fifty feet in others. As this thickness is so extremely uneven, it 
seems to me probable that the Ross Barrier is composed, certainly in its inland 
portion, and probably in its sea face, of the fanned-out ribs of glacier-ice derived 
from the contributing glacier valleys which pour into its sides, both from the 
south-east and from the south-west. JI think, then, that this great variability of 
thickness is proof that there is something more than mere sea-ice and old 
névé deposits (not but what the latter is an important contributor) helping to 
form that wonderful ice-mass, which was, perhaps, paralleled by the Pleistocene 
North Sea ice-sheet of Europe, which impinged upon the shores of Yorkshire, 
and produced those big lakes near York itself. 
Next the question has been raised as to whether the land-mass of Antarctica 
has been fixed at the South Pole from early geological times, or whether it has 
migrated. In Cambrian times we know that there was an extensive development 
of the Archeocyathine limestones. These have been described by Mr. Taylor. 
Quite lately great blocks of Archzocyathine limestone, dredged by Dr. W. S. 
Bruce from depths of about 1,700 fathoms to the north of the Weddell Sea, 
have been identified as such by Dr. Gordon. There is evidently a great develop- 
ment of these Archxocyathine limestones both on the Australian and on the 
American side of Antarctica. Mr. Taylor has shown that the Archeocyathine 
never extended into the tropical portions of the world, and on the whole were, 
therefore, probably inhabitants of cool waters. This evidence suggests that the 
axis of rotation of the earth, so far as the Southern Hemisphere, and probably 
the Northern Hemisphere too, are concerned, was perhaps approximately where 
it is now, even as far back as Cambrian time. One cannot, of course, press this 
statement until a great many more localities for the occurrence of the Archzo- 
cyathine have been identified. The problem of the occurrence of a Permo- 
Carboniferous flora within 5° of the South Pole itself will no doubt be touched 
upon by Professor Seward. 
In regard to the possible biological analogue of modern Antarctica with 
Permo-Carboniferous Australia it may be stated’ that in Antarctica we find an 
abundance of the ‘sea mats,’ a feature which attracted special comment as far 
back as the date of Sir James C. Ross’s Expedition. Similarly, we find that 
Fenestellide are very common in our Permo-Carboniferous beds, both in the 
Lower and Upper Marine Series, both of which are partly glacial in origin. 
In the Antarctic we find a large pecten, Pecten Colbecki, enormously 
abundant in the raised beaches, where it dominates every other form of mollusc. 
Also in Antarctica we find that sponge spicules are extraordinarily abundant; 
indeed, the floor of the Ross Sea must be as white as snow with sponge spicules. 
In the Permo-Carboniferous rocks of N.S. Wales large Aviculopectens are very 
numerous, and sponge spicules not uncommon. 
A point which I wish to emphasise because it is perhaps new, is that in our 
Permo-Carboniferous rocks we have a widespread development of curious mineral 
in our marine semi-glacial beds, to which we have given the name of ‘glen- 
donite.’ This glendonite is associated with glacial erratics; we find it parti- 
cularly in our Upper Marine Permo-Carboniferous rocks. It is a pseudomorph 
after glauberite. Sir Thomas H. Holland tells us that, in Lake Sambha in 
Rajputana, soda sulphates, with a little sodium chloride, are concentrated and 
thrown out in the water in winter, on account of the sulphates being less soluble 
in cold water. Mr. H. T. Ferrar, to whom members of the Shackleton 
