THE AUSTRALIAN NATURALIST. 67 
exhibited were collected and given to me by Professor Spencer, 
to whose kindness ] am in many ways indebted. 
Another Australian ant, very common on the Blue Moun- 
tains (Camponotus intrepidus), constructs a curious chimney 
or tube at the entrance to its nest. The tube is composed 
of sand-grains and tiny bits of vegetable matter somewhat 
loosely cemented together, and is frequently as much as three 
inches in height by about half an inch in diameter. It is 
-by no means clear what object is served by the tube, it is cer- 
tainly not for keeping out water, as it is much too fragile 
and porous for that, and the nests are usually constructed 
in well-drained places. <A series of these tubular nest en- 
trances is on the table. Another extremely common and 
conspicuous ant is the dark “‘Bull-dog’’? (Myrmecia forficu- 
tu), with its formidable sting and large forceps-like jaws. ‘Chis 
is an extremely pugnacious insect, and vigorously resents any 
interference with its nest. | On one occasion I found an ant 
of this species which had lost its abdomen and one of its hind 
legs, hopping about quite active and lively, on duty guarding 
the entrance. One can only speculate how it came to be so. 
severely maimed, probably it was in the execution of its 
duties. At first sight I did not recognise what kind of creature 
it was. In spite of such a serious disability it gave no evi- 
dence of being inconvenienced. Having carefully preserved 
this intrepid sentinel, I am able to show it to you. 
Many species of ants all over the world derive part of their 
food supplies from the sweet secretion of different kinds of 
‘Coccidae, Aphidae and the larvae of Psyllidae and other in- 
sects infesting Eucalypts and many other plants. These are 
commonly known as ‘‘ant-cows.’’ A very large and helpless 
Coccid, Lecanopsis filiceum, Mask., occurs commonly in vari- 
ous parts of Australia on the undergrouud rhizomes of the 
bracken fern within the burrows of an ant, Iridomyrmex. 1 
have frequently found them under logs where the ants had 
built their nests. This creature is about half an inch in length 
and is of a dark-brown colour, and possesses very small in- 
conspicuous limbs, which are quite useless for walking. It 
<lepends entirely on the ants for its well-being. The ants 
appear to look after the young, placing them in suitable posi- 
tions on the fern rhizome, to which they attach themselves 
by means of the proboscis and a whitish gummy secretion. 
When once attached they do not shift. They live entirely 
on the sap of the plant. A small Aphide, Aphis avernae, 
occurs in a similar manner on grass stems in the nest of a little 
ant (Zridomyrmex), while another, Dactylopius sp., lives on 
the rootlets of Hucalyptus, and is also the host of an ant, Z7ry- 
domyrmex gracilis. 1 am able to show you the specimens of all 
of these. 
