DE8 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
various depths. As the most significant general result Murray, in his © 
‘‘Preliminary Report” (1876), says: 
Everywhere we have found a rich organic life at and below the surface of the 
ocean. If living individuals are scarce at the surface, below it the tow net commonly 
discloses numerous forms, even to a depth of 1,000 fathoms and more (5, p. 536). 
In 1875, on the journey through the North Pacific Ocean (from Japan 
to the Sandwich Islands), the extremely important fact was established 
that the pelagic organisms in oceanic zones of different depths belong 
to different species; fine pelagic nets (or tow nets) ‘‘on many occasions 
were let down even to depths of 500, 1,000, and 2,000 fathoms, and 
thereby were discovered many swimming organisms which had never 
been captured hitherto, either at the surface of the ocean or at slight 
depths (up to 100 fathoms below the surface)” (6, p. 758). The most 
characteristic forms of these zones of different depths belong chiefly to 
the class of the Radiolaria, especially to the order of the Phwodaria. 
Through the investigation of the Challenger radiolaria, which occupied 
for ten years the greater part of my time and attention, I was led to 
study anew these conditions of distribution; and I reached the con- 
viction that the differences discovered by Murray in the pelagic fauna, 
at different depths of the ocean, were still more significant than he 
assumed, and that they had the greatest significance, not merely for 
the radiolaria, but also for other groups of swimming oceanic organisms. 
In 1881, in my “ Entwurf eines Systems der Challenger Radiolarien,” p. 
422, I distinguished three groups: (a) pelagic, living at the surface of 
the calm sea; (b) zonary, living in distinct zones of depth (to below 
20,000 feet); and (c) profound (or abyssal) animals living immediately 
above the bottom of the deep sea. In general, the different character- 
istic forms correspond (to below 27,000 feet) to the different zones. 
Inmy “General Natural History of the Radiolaria” (4, p. 129) Ihave 
established this distinction, and have expressed my conviction that it 
is possible, by the aid of a suitable bathygraphic net, to demonstrate 
many different faunal belts overlying one another in the great deep- 
sea zones. 
The existence of this “intermediate pelagic fauna,” discovered by 
Murray, inhabiting the zones of different depths of the ocean between 
the surface and the deep-sea bottom, which I have briefly called ‘ zon- 
ary fauna,” has been decidedly contradicted by Alexander Agassiz. 
He claimed, on the ground of ‘‘exact experiments” carried on during 
the Blake expedition, in 1878, that the greater part of the ocean con- 
tains absolutely no organic life, and that the pelagic animals go down 
no deeper than 100 fathoms. ‘The experiments finally show that 
the surface fauna of the sea is actually limited to a relatively thin layer, 
and that no intermediate zone of animal life, so to speak, exists between 
the fauna of the sea bottom and of the surface” (15, pp. 46, 48). 
