resembling a very delicate, broad, and flattened valve of a bi-valve
shell, such as the genus Iridina, the part where the hinge is being a
little produced and raised, and forming the cover of the coccus which
secretes the beautiful material just in the same unexplained way as the
scale insects form the slender attenuated scales beneath which they are
born. I could not discover any insect beneath the specimens of Sir Thomas
Mitchell's production in a state sufficient to determine what it really
is, as I only found one or two exceedingly minute atoms of shrivelled up
insects. It is extremely brittle, and looks more like dried, white,
frothed sugar than any thing else."]

18TH APRIL.--A pigeon had flown last evening over our camp in a N. N. E.
direction, and as the ground sloped that way, and the men believed that
water was there, I rode this morning in that direction, leaving the other
horses to feed in the meantime. At two miles from our bivouac I found
some hollows in a scrub where the surface consisted of clay, and which
evidently at some seasons contained water, although they were then dry.
Polygonum grew around them, and I doubt not that after a fall of rain
water would remain there some time. On riding two miles beyond, in the
same direction, I found open forest land only. The country was well
covered with good grass, very open, yet finely wooded. We again proceeded
north-west over some fine forest land. The soil was, however, only soft
red sand, and made it very heavy work for our horses drawing the
watercart.

On passing through a Casuarina scrub, we entered upon a different kind of
country as to wood and grass, the soil being much the same, or still more
loose and sandy. The surface bore a sterile heathy appearance, and the
trees consisted chiefly of a stunted box, growing but thinly. Instead of
grass, black, half-burnt roots of a wiry plant appeared, which I