850 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
A sensation was one day created by the discovery of great im- 
prints in the snow which at first suggested some large terrestrial 
animal; but they were soon recognized as traces of the webbed fect 
of the giant petrel (Ossifraga gigantia). 
In reality, all the truly antarctic fauna are dependent on the sea 
and are limited to the floating pack-ice or to the coast glaciers. 
The marine feeding grounds of Ross Bay seem to superabound 
in diatoms. This at least is what we are led to believe by the ex- 
treme richness of the fauna which the more or less ephemeral pack 
covering conceals. Of their richness the naturalists of the és- 
covery had direct proofs through the fishery which was carried or. 
constantly in spite of the covering of pack-ice, and also indirect 
proofs in the continual presence of seals and in the contents of their 
stomachs. A world of animal lfe thrives under the pack-ice; there 
are first, on the sea bottom, innumerable hordes of voracious amphi- 
pods belonging to the species Orchomenopsis Rossi of which a single 
dip of the net brought up from 10,000 to 30,000; the living fish used 
as bait were often devoured by them, leaving but the skeleton behind. 
Mr. Walker thinks that numbers of seals which perish by as- 
phyxiation undef the pack-ice are devoured by these amphipods. 
An abundant fauna of Crustacea, Schizopeds of the family of the 
Huphausia, move about with the fish and the cephalopods in the in- 
termediary waters. ‘The Huphausia cristallorophias, of which the 
expedition brought back 10,000 specimens, is the most common spe- 
cies under the ice; it 1s upon this species that the Manchots feed. 
It was not easy to procure fish owing to the seals, which move about 
constantly under the ice, having adopted the custom of robbing the 
nets. Nevertheless, the expedition brought back a certain number 
of specimens, mostly very small, belonging to the genera Notothenia, 
already studied at length by the Belgica, 7rematomus, and Bathy- 
draco. It is interesting to note that the seals procured for the ex- 
pedition two very large fish, one of which was more than a meter 
long and 18 kilograms in weight. The fish of the cold seas being 
ordinarily very small, this detail attests the zoological richness of 
these waters. It should be noted that the waters of MacMurdo 
Sound are constantly renewed by currents and that their tempera- 
ture scarcely varies more than 1° C. in the course of the year, oscil- 
lating between —2° C. and —1.1°. We do not dwell on the numerous 
animal species that swarm in these waters of relatively medium tem- 
perature—Hydroides, Pyenogonides, and various sponges. They 
are the subjects of detailed description in the collection of the 
Discovery, but of interest to naturalists more than to geographers. 
There is reason for dwelling longer on the higher fauna which 
flourishes in this sea, cold but swarming with life, and which adds 
its characteristic tone to the marine or littoral pastures of Victoria 
