Oct., 192u 
The (Queensland Naturalis^. 
97 
The basalt is very rich in olivine and is composed of 
olivine, felspar (plagioclase), augite, magnetite, and 
ilmenite. The plagioclase is much less abundant, and the 
olivine much more so in this rock than in the basaltic rocks 
of Oueensfand. The olivine occurs'" frequently as nodules 
or accumulated masses, which are sought for gem purposes, 
and individual crystals range in size from -44 mm. in 
diameter down to very small granules. 
The specific gravity of the rock is 2-88, and a chemical 
analysis made in the laboratory of the Agricultural Chemist,. 
Brisbane, gave the following results ; — 
Per cent. 
Silica 
• • 50-27 
Alumina 
. . 12.50 
Ferric oxide 
2.44 
Ferrous oxide 
. . 8-i8 
Magnesia 
■ ■ 10-25 
Lime 
7*52 
Soda 
3.29 
Potash 
1.42 
Water 
i-6o 
Titania 
0-67 
Phosphorous pentoxide . . 
o-6o 
Manganese oxide . . 
o-6o 
Total 
• - 99-34 
PREDACEOUS GROUND BEETLES. 
By R. Illidgk. 
Genus, Castelncaudia. This was formerly HoniaJosoma 
and TrichosternuSj but, both being preoccupied, the present 
title has been suggested by a Russian writer on Carabidae, 
and adopted by students of the family. It commemorates 
the name of the noted naturalist Count de Castelneau. 
During a Field Naturalists' trip to Goodna Scrub in 
March, 1919, I took a species of the genus which I then 
considered >’as C.. renardi, but on,i*taking it out to pin. at 
once saw it had no resemblance to that insect. It appears- 
to be nearest to C, cordata, but is larger than that species, 
and the elytral disc is flatter. 
The capture of this insect suggested that a few notes 
on the natural history of the genus, and also its great 
