1438 
THE VOYAGE OF H.M.S. CHALLENGER. 
Comparison ok 
THE Species cap- 
tubed AT SEVERAL 
Deep-Sea Sta- 
tions, IN VARIOUS 
Regions or the 
Ocean. 
the area is much more restricted. For instance, large hauls were obtained at Station 
24G in the North Pacific, and at many stations in the North Atlantic explored by the 
“ Porcupine,” “ Valorous,” “ Triton,” and “ Knight Errant.” The greater number of animals 
on the sea-floor in the Southern Ocean, the North Atlantic and Pacific, may, however, 
be connected with migrations of Benthos animals equatorwards from polar regions. 
It is usual to assume that there is a universal and peculiar fauna of great antiquity 
in the deep sea. An examination of the statistics given in the foregoing pages does 
not seem to confirm this opinion. Let us further compare some of the results of 
deep-sea trawlings in different regions of the ocean. 
In 1850 fathoms in mid-equatorial Atlantic (Station 106), and in 2425 fathoms 
mid-equatorial Pacific (Station 271), both on Globigerina Ooze, 66 species were 
obtained, 38 species in the first and 29 in the second Station, but only one species 
— the little Discina atlantica — was common to the two localities. The genus Discina 
ranges from the Cambrian to the present time. 
In 1875 fathoms in the Northern Pacific (Station 237), and in 2050 fathoms 
(Station 246) also in the North Pacific, and in nearly the same latitude (35° N.), but 
separated from each other by about 1790 miles, 100 species were obtained, 57 species in 
the first and 48 in the second Station, and of these only five species were common to the 
two stations. 
In 1375 fathoms in the Southern Ocean (Station 146), and in 1600 fathoms (Station 
147) also in the Southern Ocean, and in nearly the same latitude (46° S.), but separated 
by only 122 miles, 145 species were obtained, 78 species in the first and 89 in the 
second Station, 22 of which were common to the two stations. 
There is not one species common to the six above-mentioned stations. If we take 
the above two tropical stations as one group, the two Northern Pacific stations as a 
second, and the two Southern Ocean stations as a third group, then of the 290 species 
recorded from all three groups only two species — Macrurus armatus and Eucopia 
aicstmlis — or 07 per cent., are common to all the three groups. In the Northern Pacific 
and equatorial groups 160 species were obtained, of which only 6 species, or 37 per 
cent., were common to these northern and tropical Stations. In the Southern Ocean and 
equatorial groups 208 species were obtained, of which only 4 species, or 1'9 per cent., were 
common to these soutlieni and tropical Stations. In the Northern Pacific and Southern 
Ocean groups 235 species were obtained, of which 10 species, or 4’2 per cent, were 
common to tliesc Stations from high northern and high southern latitudes. Discina 
atlantica, Ilyocrinns hcthellianus, Ilyalonema {Stylocalyx)depressum, Bugula reticulata, 
Liponerna multiporum, which live attached to the bottom, are among the species 
common to two or more of the above Stations, but the majority of the species common 
to two or more Stations belong to Fishes and Crustaceans which move freely over the 
