No. 4. — A Visit to the Great Barrier Reef of Australia in 
the Steamer “ Croydon,” during April and May, 1896. By 
ALEXANDER AGASSIZ. 
THE EASTERN COAST OF QUEENSLAND. 
No better introduction can be given for the study of the problem of 
the evolution of the Great Barrier Reef of Australia than a general sketch 
of the Physical Geography of the Northeast Coast of Australia from 
Moreton Bay to Cape York. І shall illustrate my remarks by a scries 
of charts and sketches of the most characteristic parts of the coast, se- 
lected with special reference to our subject. (Plates XXIII. to XXXVI.) 
These will show the gradual encroachment of the sea upon the northeastern 
edge of the continent of Australia. We shall then follow the submarine 
extension of the coast, and from the soundings given on the English 
ILydrographie Charts select a number of lines across the continental 
platform which will give us a fair idea of the sea-face slope upon which 
the outer edge of the Great Barrier Reef is situated. (Plates XXXVII. 
to XLL) This will be followed by a few charts illustrating that part 
of the reef which we examined somewhat in detail, and from which 
I have ventured to build up an explanation of the causes which have 
been mainly efficient in the shaping of the Great Barrier Reef as 
it stands to-day. 
Beginning at the latitude of Brisbane, the coast is flanked by the 
islands of Stradbroke and Moreton, both of which rise to over’ six 
hundred feet (Plate XXVI). The former island is separated from the 
mainland at its southern extremity by a shallow and narrow passage, 
while towards the north the island is separated from the mainland by 
a number of low islands, one of which attains a height of 250 feet. 
Between the islands, flats and bars are left uncovered at low tide 
between the deeper parts of Moreton Bay. Similar banks and islands 
flank the right bank of Brisbane River near its mouth. Moreton 
Island is separated from the mainland by a series of bars and flats 
running in a northerly direction, between which run the two principal 
VOL. XXVIII, — NO, 4. 
