W. A. HASWELL. XLIX. 
fauna existing there permanently: a fauna doubtless intro- 
duced originally in a fortuitous manner from the surface 
waters ; but now established permanently underground, a 
fauna differing in a sensible degree from that which now 
inhabits the surface waters. It is this last consideration 
which lends its main interest to an investigation of this 
subterranean aquatic fauna in Australia. While the fresh- 
water animals inhabiting the rivers and lakes of the surface 
have been subject at intervals to wholesale destruction 
owing to the complete desiccation of rivers and lakes in 
time of drought, the subterranean fauna may be supposed 
to have been protected from this destructive influence; 
and it is not too much to hope that forms no longer repre- 
sented in the surface fauna may survive in the artesian 
underground reservoirs. 
When I first began some inquiries into this subject a few 
years ago, I found that there were rumours in abundance 
of animals—fishes for the most part—having been dis- 
charged from the bores; but there was apparently an 
absence of trustworthy evidence that they had actually 
passed out in the artesian water. It is well known that 
when new dams are formed, even at a considerable distance 
from other water, a population of crayfishes, water-snails, 
and mussels, water-beetles and other aquatic insects, and 
frogs and fishes, appears in it with what seems remarkable 
rapidity: and such a development, in the case of the new 
dams and tanks filled with the artesian water, might lead 
to the erroneous conclusion that the animals in question 
had actually issued forth in the stream from the sub- 
terranean reservoirs. To prove that any animal is in 
reality a member of the artesian fauna, it must not be 
merely picked up in the neighbourhood of the bore, but 
must be actually caught in the act of issuing forth from 
it. For the purpose of collecting such artesian animals 
4—July 20, 1903. 
