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THE ESSEX NATURALIST.
The thorax carries the 6 legs and the organs of flight. The
legs are characterised by the tarsi having 3 joints, except in a
few families in which they have only 2. In the Cryptocerata
(excepting Nepa and Ranatra,) the hind pair of legs are broad,
flattened, and fringed with hairs to form oars for propulsion
through ths water. That part of the thorax known as the
"scutellum" is an outstanding feature of Heteroptera. It is
always more or less triangular in form, and reaches its greatest
development in the Pentatomidae, in some species of which it is
nearly as long as the abdomen, over which it extends. Except
in one particular, the abdomen is not particularly noteworthy
in most species, but in the Pentatomidae and Coreidae its margin,
called the "connexivum," is broad, flattened and often strikingly
coloured. In most bugs the ovipositor is simple, but in the
Lygaeidae, Tingidae and Capsidae it is furnished with teeth or
cutting edges with which to pierce the tissues of, plants, in which
the eggs are laid. The objectionable feature of the abdomen
is the presence of 2 stink-glands, the orifices of which are situated
on the underside near the second pair of legs. The volatile
effluvium emitted from these glands is exceedingly unpleasant
in the Pentatomidae, Cimicidae, some Coreidae and Capsidae, and a
few others ; in many species, however, the smell is not at all
obvious, and in one at least, Coranus subapterus, it is said to be
actually pleasant, resembling the scent of ripe pears. This
is the more remarkable, because its near ally, Reduvius personatus,
sometimes called the Fly-bug, not only stinks abominably, but
the puncture of its rostrum is reputed to be poisonous. It has,
however, one redeeming feature, as it feeds greedily on Bed-
bugs, when it can get them. Both Coranus and Reduvius
have the power of stridulating, or chirping, the sound being
produced by rubbing the tip of the rostrum along the transversely
striated furrow on the presternum, or chest. These two species
are much alike in general appearance, except that Reduvius
is fully winged, whilst Coranus is usually brachypterous. The
Notonectidae and Corixidae can also stridulate, even under water,
and I need not remind you of the famed singing of the Cicadas,
which, as already stated, belong to the Homoptera.
The sexes of the Heteroptera are very similar in appearance,
except that the males are often smaller, slenderer and more active,
than their mates. In a few genera, however, there is conspicuous