AGASSIZ: THE GREAT BARRIER REEF OF AUSTRALIA. 103 
Guinea, or eroded the archipelago lying between them and the chan- 
nols of moderate depth separating the islands and flats which have 
been cut by tho tides, currents, and action of the sea. 
Beyond the 100 fathom line there are a number of detached reefs, 
which seem to indicate tho existenoo of very extensive plateaus of 
moderate depths extending off the continental plateau of the Great 
Barrier Reef, as, for instance, off Swain Reefs : the Saumarez Reefs ; in 
the channel separating them from the continental plateau, 199 fathoms 
is indicated; in the latitude of Port Denison, 230 fathoms is the 
greatest depth found in the channel 120 miles wide separating Marion 
Reef from the continental slope. 
In the latitude of Flinders Pass to Cook’s Passage there is a channel 
of about sixty miles in width, varying from about 600 fathoms to 1,300 
fathoms, which separates an immense triangular plateau, bounded to the 
eastward by the 1,000 fathom line, 250 miles by about the same base 
with a depth varying from 800 to 300 fathoms, upon which crop out a 
number of reefs: the Flinders Reef, Flora Reef, Herald Cays, Holmes 
Roof, Osprey Reef, Diana Bank, Willis Group, Magdolaine Cays, Tre- 
gosso, and Lilian islands and reefs. Unfortunately no soundings exist 
to show whether these banks are connected, and are parts of a single 
plateau, or are separated by deep channels. 
THE GREAT BARRIER REEF. 
We may now proceed with the description of the coral reef flats and 
KR 
patehes, which we examined on our way from from Breaksea Spit to the 
Lizard Islands? (Plates XXIV., XXV., XXVII. to XXXIV.). 
1 See the conclusions of an interesting paper by Professor Haddon on the geo- 
logical relationship of Queensland and New Guinea, ("Transactions of the Royal 
Irish Academy, 1894, Vol. XXX. p. 467,) and descriptions and sketches of some 
of the reefs in the Torres Strait scattered through his account of the geology 
of the Strait, Гос. cit, page 420 and following. 
2 Professor E. S. Dana published an extract from a letter to him dated Cook- 
town, Queensland, May 16, in the September number of “ The American Journal 
of Science," 1800, p. 340, giving a summary of the results obtained during my 
visit to the Great Barrier Reef. 
The steamer “Croydon” of the A. U. S. М. Co. was chartered for my explora- 
tion of the Great Barrier Reef. Dr. W. Мем. Woodworth and Mr. A. G. Mayer 
accompanied me as assistants. We carried a complete photographie apparatus and 
an extensive outfit for pelagic fishing in the way of surface as well as of deep-sea 
Tanner nets, with the usual apparatus for sounding in moderate depths. АП this, 
