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not found South of Sharks Bay with one peculiar exception— the 
Houtman’s Abrolhos — islands situated about 30-50 miles off the 
Australian coast in Latitude 28° 30' S. The fauna of Sharks Bay is, 
in fact, almost tropical, but a rapid diminution in the number of these 
tropical species occurs as one follows the coast southward, until at 
Albany one meets with some typical Antarctic elements. The 
Abrolhos Islands occupy a rather interesting position, and Saville 
Kent, after a visit, stated that the marine fauna was not only a 
blend of tropical and temperate species, but that the tropical species 
were not found on the adjacent coast. The Hamburg Expedition 
did not visit these islands, but the members apparently agreed with 
the views expressed by Kent after an examination of certain collec- 
tions in the West Australian Museum. With these statements in 
mind, and the fact that the Islands were good collecting grounds for 
the marine biologist, Mr. W. B. Alexander, of the West Australian 
Museum, and I visited the Abrolhos last November. Extensive 
collections were made and these will be worked up in due course by 
specialists on the various groups. One of the questions which calls 
for investigation is the problem of the Hydrographical Conditions. 
If an examination of the fauna of the Abrolhos supports the views 
of Saville Kent, then what is it that determines the Southern exten- 
sion of tropical organisms at this place? The study of the hydro- 
graphy of this region is but a small section of an investigation 
which is called for along the entire coast. 
The islands are, so far as we could see, entirely composed of 
up-lifted and wave-heaped coral. There is no evidence whatever 
for the statement of Saville Kent that plutonic rocks corresponding 
to those of the mainland occur in the Wallaby Group. The Wallaby 
Islands, like the others of the Abrolhos Group, are coral formations. 
The rich growths of coral would certainly encourage us to look for 
some influential hydrographical conditions. Let me discuss some 
of the information that we now possess and some of the theories 
put forward. 
Saville Kent stated that he found the sea temperature was 
14° F. higher at the Abrolhos than at Geraldton on the coast at the 
same time, and during the month of July, 1894. He suggested that 
a warm current of water came down from the Tropics — a Southerly 
intrusion of an equatorial current perhaps not exactly reaching 
the islands, but approaching them. Kent did not give sufficient 
details of any temperature observations made by him. Michaelsen, 
who has stated that one must travel about 6° latitude North of Sharks 
Bay in order to meet a coastal fauna similar to that of the Abrolhos, 
believes that if a warm current does exist it is not the only factor. 
His suggestion is that an upwelling of cold water takes place along 
the coast which is driven outwards along the surface. Quite apart 
from our studies, it is important from the point of view of fishery 
investigation that we should know something of the movements of 
