26 THE AUSTRALIAN NATURALIST. 
Tur Orprnary Montuty Mesrine was held at 82 Pitt Street, 
on Thursdny Evening, June 7th, 1906. The President in the 
chair. 
Execrion to Mempersuip.—Mr. H. EH. Baker, Gundy, N.S.W. 
Paper —Mr. J. H. Maiden, F.L.S., read a paper on “ Some 
Acacias of the neighbourhood of Sydney,” with numerous 
mounted specimens and drawings in illustration. 
A discussion on the function of the glands on some wattles 
and other plants followed. Mr. Gurney mentioned observing 
the common aphis-eating ladybird Coccinella repanda feeding 
on juice on the glands of the cow pea. ‘This and other species 
are found on wattles and he thought it possible such predaceous 
species may rely on gland products for food in the absence of 
scale or aphis food. 
THE GEOLOGY OF THE SHOALHAVEN. 
By C. F. Laseron, 
A. short time ago, accompanied by two friends, Messrs. Youll 
and R. Condy, I visited the Shoalhaven district. Our original 
intention, on first undertaking the excursion, was to proceed 
right up the river from Nowra, for a distance of about 80 miles, 
but, unfortunately, rain and a consequent fresh in the river, 
besides the fact that we were shorthanded, caused us to halt, 
and make a permanent camp at the junction of Yulwal Creek 
and the Shoalhaven, a point about 30 miles from Nowra. 
The first feature of the district is its extreme roughness. 
We here stand, geologically speaking, on the edge of the great 
Permo-Carboniferous coal-basin. The Southern Plateau slopes 
gradually away to Sydney, owing toits gradual dip northwards. 
But on its Southern, or rather South-eastern boundary, it has 
been dissected by the Shoalhaven and its tributaries, leaving 
great gullies and gorges, striking monuments of the potency of 
river erosion aided by atmospheric denudation. ‘he river, 
during a long period of slow upheaval, has cut its way right 
through the Permo-Carboniferous and into the Devonian, ex- 
posing along the river bank beautiful sections of unconformity. 
The Devonian rocks are, on the whole, very devoid of fossils, 
and it was a considerable time before we found a fossilferous 
horizon. In loose boulders of quartzite, in the bed of Yalwal 
Creek, we found Pterinea, Leptodonius, Monticulipora, etc., 
associated with Rhynconella pleurodon. At the junction of 
Yalwal and Extrema Creeks we found fossils in situ, amongst 
which were Avicula fosseletia (?), Sphenotus, Goniophora, 
Allorisma, ete. On the Shoalhaven River, about four miles 
above its junction with Yalwal Creek, another outcrop was 
discovered, possibly continuous with the last. Here fossils 
