shelf. A correct series of surface to bottom temperatures, taken as 
one passes out from the coast until deep water (over 200 fathoms) 
is reached, would doubtless settle this case. We have the apparatus 
and it is merely the question of obtaining the loan of a suitable 
steamer for a day or so, perhaps four times a year, which prevents 
us from obtaining the figures. 
Our nearest Coral Islands — the Abrolhos. 
The Abrolhos Islands have already been mentioned several times . 
in this address. As a matter of fact it is very probable that these 
islands' will be one of our most conveniently situated and richest 
collecting’ grounds for some time to come. They are probably the 
most southerly coral islets in the world, and, since the question of 
coral reef formation is still a much discussed problem, their close 
vicinity to Perth should enable us to collect some important in- 
formation. I am afraid that their distance from Perth is not ex- 
pressed correctly by merely referring to it in miles. It should be 
expressed in time, or in money, for it is not so easy to reach the 
Abrolhos as a resident in another land might imagine after using 
his atlas. 
There are several groups of islets making up the Abrolhos 
which are separated by channels. From North to South they are 
as follows: — The Wallaby Islands with North Island — the Easter 
Island Group — The Pelsart Group. The northerly islands attain 
the greatest heights above sea level (maximum between 40 and 50 
feet only) and appear to have been subjected to the greatest altera- 
tion by uplift and denudation. The Pelsart Group is quite atoll- 
like in character, and the individual islets are only a few feet above 
the sea level. The Wallaby Islands at least have been connected 
with the mainland in comparatively recent times (geologically speak- 
ing), and the land fauna is consequently rather curious now by 
reason of the wallabies, reptiles, and amphibia which abound on 
these small coral islets 50 miles away from the coast. 
It is difficult to speak with any certainty about the early forma- 
tion of the Abrolhos Islands, especially since theories of the forma- 
tion of coral islets, where the sequence of events has not been com- 
plicated by elevation and subaerial denudation, have so far not been 
exactly successful. 
It does not seem probable, however, that the atoll-like Pelsart 
Group has developed in the way suggested by Darwin. There is 
evidence everywhere of the action of the sea. 
The two Wallaby Islands have been separated by erosion and 
solution, and very many of the islands are now being cut away to 
the mean sea level by the action of the waves and currents. Most 
of the cliffs overhang, and this undercutting continues until huge 
blocks break away. 
