go 
Mahogany Creek — a microcline-oligoclase-biotite rock. In the 
section cut the felspars are very clouded and are therefore difficult 
to determine. Slight traces of gneissic structure are seen at times 
in this rock. A pegmatite vein in the quarry is composed largely 
of microcline. Veinlets of epidote are seen in places. 
In the western quarry work has been concentrated on a dyke of 
quartz diorite, the rock being crushed for ballast. This dyke is inter- 
esting on account of the numerous schlieren in it. These are much 
coarser grained than the average rock and are composed largely 
of amphibole of two species, with which are associated large 
skeleton crystals ol ilmenite. In the main mass of the dyke 
the latter mineral is represented by numerous large pseudomorphs 
of leucoxene. 
GOSNELLS. — October i, 1910. Leader, Dr. C. G. Thorp. 
The excursion to Gosnells took place on October 1. There 
were fifteen members and their friends present and a very enjoy- 
able afternoon was spent in spite of swamps, hills and heat. 
The geological party, of which I constituted myself one, un- 
fortunately missed the mine which is in the locality, and will be 
visited the next time we go to Gosnells. 
Dr. Tratman took charge of the botanical section, and 
reports as follows Gosnells is at any time of the year a good 
botanical hunting ground, but is especially so before the swamps 
at the foot of the hills have dried up. The following is a list of 
plants in full bloom on this date.: — Microtis parviflora , Glossodia 
emarginala , Thelymitra crinita, T. villosa, Diuris setacea, Calythrix 
glutinosa, Ander sonia latifolia, Melaleuca scabra, Verticordia in- 
signis, Conothalmnus trinerris, Microcorys longijolia , Utricularia 
hookeri, Slylidium carnosum, Thomasia glutinosa, T. Montana. 
Mr. Giles, who had charge of the entomological section, has 
furnished me with the following particulars : — The entomological 
results w’ere hardly worth the time expended in the search, es- 
pecially so if one considers the extent of ground covered during 
the afternoon. With the exception of the common “Painted 
Lady ” butterfly ( Pyrameis car did, var. /c ershawi), no Lepidoptera 
were observed, but we found a few' of the nut-like cocoons of a 
species of Limacodes moth, not previously taken in the State. 
This w’e are in hopes of hatching out later on, then if success 
favours us we shall be glad to exhibit them at a future meeting 
of the Society. A few scarce but known Coleoptera were captured. 
Owing to the unfavourable weather conditions, none of the other 
orders were taken. 
Geology. — Mr. E. S. Simpson has supplied the following 
notes on geological features : — The Gosnells railway station is on 
