72 THE AUSTRALIAN NATURALIST, 
to show you specimens of the curious little fresh-water crab 
Hymenicus varius (Hymenosoma lacustris, Chiltern), which 
occurs abundantly in Lake Takapuna, an extinct crater form- 
ing a beautiful little lake some distance from Auckland, and 
has also been found on Lord Howe Island, in Victoria and 
Tasmania. This little crustacean appears to feed principally 
on a fresh-water sponge (Spongilla) which grows to a remark- 
ably large size in the same lake. Specimens of both are ex- 
hibited. 
Amongst the animals of New Zealand which have become 
extremely rare and which, if not extinct, exist now only in very 
circumstanced localities, are the Frog, Liopelma huchstettert, 
and the Maori Rat, JI/us exulans. L. hochstetteri is the only 
indigenous frog in New Zealand, and has always been extreme- 
ly rare. It was first discovered in 1852, and Hochstetter states 
that even then it was so scarce as to be unknown to the natives. 
The specimen exhibited shows it to be a very beautifully 
marked creature. 
The Maori rat, though not confined to New Zealand, being 
found in certain of the South Sea Islands, is now extinct in 
New Zealand except in one or two of the Barrier Islands. It 
is an interesting little creature, and has quite a classic his- 
tory, the tradition being that it was brought from their ori- 
ginal home, the island of Hawaiki, by the Maori who first 
went to New Zealand, so that it is well named exulans, the 
wanderer. It was much prized as an article of food by the 
Maori, and consequently was a scarce animal when the first 
white men visited New Zealand. It is related that a Maori 
chief on seeing the large European rats on board a ‘visiting 
vessel, begged the captain to liberate some of them on the 
land so as to provide a larger game animal than their own 
rat. The Maori name for the native rat was Kiore. 
And now a word or two in conclusion on the subject of the 
preservation of dry natural history specimens, and particu- 
larly insects. For many years I have experimented with dif- 
ferent methods of treating insects to render them impervious 
to the pests which so quickly ruin a collection when not con- 
stantly watched and kept well supplied with napthalene or the 
like. For a long time a solution of corrosive sublimate in 
spirit in which the insects, after setting, were dipped, was the 
best I knew. Contrary to what one might very naturally 
expect, however, the protection afforded by this very poison- 
ous substance is of the most transitory nature, it being effective 
for only a very few months. The corrosive sublimate appears 
to gradually volatilise, leaving the specimens an easy prey to’ 
their enemies. These remarks apply to a solution of about 4 
grains per ounce, which is as strong as can be used on beetles 
and such-like without causing a white incrustation on the sur- 
