104 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Breaksea Spit (Plate XXIII.) may be said to be the dividing line 
between the Barrier Reef coral district and the southern extension of 
corals, which, though belonging to reef building species, yet have no- 
where flourished luxuriantly enough to build more than thin stretches 
of coral patches, the southernmost limit of the coral fauna being 
Moreton Bay, at the mouth of the Brisbane River, As has already been 
observed by Kent, the corals of that part of the Queensland coast are 
limited in their development by local causes, and in the southern ex- 
tension of the reef building corals of the Barrier Reef we find the same 
phenomena characterizing their diminished growth which mark their 
northern extension on the east coast of the United States north of the 
Florida Reef. Their disappearance in the Atlantic is, however, mainly 
due to the temperature of the water, while on the Queensland coast 
their disappearance was also affected by the great amount of sediment 
brought down the Brisbane River, and which is gradually silting up 
Moreton Bay. 
It is a curious coincidence, however, that at Breaksea Spit, as well 
as at Cape Florida, we should find the encroachment of the silicious 
sands, in one case coming from the north along the coast of Florida, 
and in the other coming from the south along the shores of Frazer 
Island, gradually prevent the farther northern and southern extension 
of coral reefs in the two regions. 
Dead corals are constantly thrown up upon the beach to the north of 
beside the necessary appliances for preserving the collections, was forwarded to 
Sydney early in the winter. 
Commander Z. L. Tanner, U. S. N., was kind enough to superintend for me the 
building of the sounding machines and of the deep-sea nets. We hoped to make 
large collections of pelagic animals, both inside the Barrier Reef as well as at sea 
off the passages leading through the reef. Unfortunately, during our whole stay 
in the distriet of the reef, boisterous weather prevented us from carrying out our 
plans for making pelagic collections, and we were compelled to limit our work 
mainly to the examination of the inner portions of the Great Barrier Reef 
district. 
І have to thank the State Department at Washington, the Foreign Office in 
London, and the government of Queensland, for the interest they took in the ex- 
pedition, and for the facilities for work offered me in consequence from every 
direction. 
I am specially indebted for valuable information and advice to Admiral Whar- 
ton, R. N., and to Commander C. D. Sigsbee, U. S. N. I owe my thanks to Mr. 
W. Saville Kent, Dr. R. L. Jack, Captain Thomson, and the officers of the € Croy- 
don," for their interest in the expedition. The managers of the Australasian 
United Steam Navigation Company and their agents from Sydney to Cooktown 
were indefatigable in attending to the wants of our party. 
