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 nourished 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 coiucidence, 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 district 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. 



I 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, T)r. 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. 



