44 
THE TASMANIAN N AT URALIST. 
Cbe Jnsects of Casmama* 
Part I. 
By ARTHUR M. LEA, F.E.S., 
Government Entomologist. 
^ have in Tasmania many insects ; how many is not yet known, 
W*. and probably will not be known for many years, if ever. But 
it is probable that we have between 15,000 and 20,000 distinct sorts. 
Some of these are extremely minute, and others are so local in their 
distribution that they are seen by but few people. To some people 
everything that crawls or wriggles is an insect, but a typical insect in 
its adult stage is divided into three main parts, the head, the thorax, 
and the abdomen, and these are usually well defined. The head con¬ 
tains the jaws or mouth parts, two compound and sometimes three 
simple eyes. Attached to it on the lop or sides are two appendages 
known as antennae, of very variable shapes — often fan-like, clubbed, or 
linear, and sometimes of greater length than the body. Attached to 
the mouth are two, four, or six small processes, known as palpi, or lip 
feelers. To the thorax are attached four or two wings, and six legs. 
There are, however, many exceptions, as with the ants, of which some 
forms are wingless, some of the scale insects, which are without legs, 
and with the body not in three distinct parts, &c, Insects also breathe 
through their sides through small openings known as spiracles, and 
there are certain other distinguishing features. The earlier stages are 
frequently very different in appearance to the adults, so that the connec¬ 
tion between them has to be worked out by rearing Some of the 
earlier stages, as with most caterpillars of moths and butterflies, appear 
to possess more than six legs, although the additional supposed legs 
are really claspers, and are attached to the abdominal segments. 
Creatures such as spiders with the body in two main parts only, 
and with eight legs ; ticks and scorpions with the body in one main 
piece, and also with eight legs ; centipedes and millipedes, with the 
body in numerous segments and with dozens or hundreds of legs, are 
not insects, although they creep about much like many insects do. 
In this part it is only intended to give a rough idea of the general 
classification, with a few figures to enable our junior members to recog¬ 
nise the particular division to which an insect he captures belongs ; as 
there are so many insects known from Tasmania, that it would be 
impossible within the small space here available to deal with them all. 
Later it is hoped to deal with the various orders separately. 
Insects are grouped in divisions known as Orders ; according to 
their structure as adults, and the changes they undergo before becoming 
adult. Some of the orders contain thousands of species, and others 
comparatively few ; whilst some very small groups have been regarded 
