~I 
SEA LILIES, STARFISHES, ETC.—CLARK. 
EcuInI. 
Phyllacanthus magnificus. 
Centrostephanus tenwispinus. 
Peronella aphnostina. 
HOLOTHURIANS. 
Caudina tetrapora. 
Colochirus axiologus. 
It is useless to speculate on the origin or significance of this 
West Australian fauna until we know the fauna of the 
north-western coast. The region between Shark Bay and 
Torres Strait should be thoroughly explored, and, as soon as 
possible, that between Melville Island and Timor. When this 
vast area is as well knownas South-eastern Australia we shall 
be able to form an intelligent opinion concerning the West 
Australian subregion. We shall know then, too, whether we 
ought to recognise a North Australian subregion, and if so, 
whence its fauna came. There are some very characteristic 
species from that district, but they do not come within the 
scope of this report. 
So far as the present evidence goes, it seems that the Western 
Australian fauna is a derivative of that of the South Aus- 
tralian subregion with a considerable element from the 
tropical Indian Ocean. The characteristic South Australian 
fauna is clearly derived from that of the east coast with at 
least a small addition from a southern fauna common to South 
Africa and southern South America. The exact extent and 
significance of this southern element is one of the most 
interesting and least known features of the South Australian 
fauna. There is little question that the Kast Australian 
fauna is derived directly from the Indo-Pacific and is still 
closely associated with the fauna of the East Indies and the 
Pacific Islands. Whether any of the east coast fauna has 
been received through Torres Strait or whether it has all come 
around the eastern end of New Guinea, or whether it is largely 
of southern origin and has spread northward and eastward, 
are still questions to be answered, but I see very little evidence 
indeed in favour of the latter view. 
In the above discussion, I have obviously omitted all 
reference to other groups of animals, believing I could best do 
my part in the solution of the problem by presenting simply 
the evidence offered by the group I am studying. I believe 
the Echinoderms are a very satisfactory group by which to 
test possible lines of migration, the great antiquity of the 
phylum, the relatively small number of genera and species. 
