82 THE AUSTRALIAN NATURALIST. 
ES ey | 
to work to dévour the legitimate inmates. In addition to the 
parasitic forms, there is an interesting group known as 
“inqualines,” and these may be defined as uninvited guests 
which feed within the tissue, or cell, of the gall, but yet do no 
injury to the rightful occupants. Hence, if a novice takes up 
the study of galls and gall-makers, he will be both puzzled 
and surprised at the extent and variety of species he will 
breed from a single type of gall. 
- The family Chalcidee embraces a large number of species of 
this group. ‘Those included in the genus Megrstigma have, in 
both sexes, narrow heads, but the females are provided with 
a bristle-like ovipositor. Some of these insects attack the 
leaves of young gum trees, causing them to swell out into 
gouty excrescences, while others are guests in soft, fleshy 
galls on the wattle and kurrajong, which result from fungoid 
diseases ; others, again, form shot or wart-like galls upon the 
foliage of all kinds of trees. Some of these wasps are of: 
solitary habits, and some are gregarious. The different 
species of Acacia are rich in galls of Hymenopterous insects, 
and these are produced sometimes upon the branchlets, and 
sometimes upon leaves and flower-buds. 
Homoetera.—Within this order is included a number of tiny 
insects much like diminutive Cicadas. These belong to the 
family Psyllide. Their larve are furnished with sharp, 
beak-like mouths, with which they puncture the tissues of 
their food-plants. Although many of these creatures are 
naked, or only enveloped in white flocculent’ matter, and 
others cover themselves with shells 01 nets of fantastic shape, 
formed from the sap of the plant, there are a number of species 
that produce well-defined galls upon the foliage of Hucalypts. 
Coccip#.—It is remarkable that, with one exception, galls 
made by scale insects are, so far as we know at present, pecu- 
liar to Australia. The trees affected by them include the Huca- 
lypts, Leptospermum, Melaleuca, and Casuarina, or She-oaks, 
Larvee born within the shelter of these galls escape through 
the pin-prick or slit-like opening at the summit of the gall. 
These larvee appear like yellow dust, but when placed under 
the microscope each speck is seen to be an oval, flattened, 
shield-shaped creature with well-developed legs, antennw 
eyes, and a short, beak-like mouth on the underside of the 
head, while the outer edge of the upper surface is fringed right 
round with short, truncate, glassy filaments. 
Galls of Australian Coccids of the sub-family Brachy- 
scélinee have no parallel in any other part of thé world on 
account of their remarkable form, size, and the difference of 
shape in the sexes. The genus Apiomorpha comes first in 
importance. The female galls are produced’ upon leaves or 
twigs, aid are either rounded, oval, or aigular. The male 
galls, which outnumber the females by thousands,’are usually 
