6 DEEP SEA FISHES. 
Previous to the year 1891 almost no deep sea collecting had been 
attempted in the equatorial regions. On other cruises the “ Albatross” 
had searched the depths off the western coasts of North America from the 
Gulf of California to Bering Sea. The same vessel and other vessels of 
the Coast Survey and of the Fish Commission of the United States had 
obtained a fair knowledge of conditions in the northwestern Atlantic 
from the Caribbean Sea northward, to which the British steamer “ Chal- 
lenger” also contributed something; the “Challenger” the “ Travail- 
leur,” the “Talisman,” and other vessels of various European governments 
rendered a like service in the northeastern Atlantic from the Cape Verdes 
and the Mediterranean northward; the “Challenger” researches added 
much to ichthyological knowledge of the northwestern Pacific and the Aus- 
tralian regions, also a little concerning the southwestern Atlantic and the 
Antarctic ; and the British Indian steamer “ Investigator”? has done a great 
deal of work in the northern reaches of the Indian Ocean. The most of 
these researches were effected far to the north of the equator and a compar- 
atively small amount was accomplished in southern latitudes. The present 
collection of the “Albatross” supplies data from the waters under the 
equator and in a measure provides the means of connecting the results 
obtained in the north with those from the south, which latter, however, 
pertain almost entirely to the shoal water fauna of that region. 
Genera of animals known toward the Arctic regions having been found 
to occur in the Antarctic, to some extent the fact that they had not 
been carefully sought in the equatorial waters was overlooked, and a theory 
of a bipolar distribution with absence from the torrid zone was accorded 
a considerable amount of favor. Acceptance of this theory was not at 
all general, for as early as 1880 Giinther had published his belief that 
separate horizontal regions could not be distinguished in connection with 
the fishes of the abyssal fauna, yet it was not until 1891, in the present 
collection, that abundance of material proof that the belief was well founded 
was secured, — proof that the bipolar theory could not apply to the bathy- 
bial fishes. So many of the least expected families appear in the collection 
that there are doubts of the absence from the localities from which it 
was gathered of any of the fishes of the deep sea. The presence of 
Raix, Pediculates, Discoboles, Gadoids and Myxinidx, among others, leads 
one to anticipate the occurrence in the same areas of any of the known 
fishes of great depths. If the collection is compared with collections made 
