skill of a DIVINE MECHANICIAN are singularly conspicuous, and which
appears to be without a parallel in the insect world, may be seen in
the under-lip of the various species of dragon-fly (_Libellula_ L.).
In other larvæ this part is usually small and inconspicuous, and
serves merely for retaining the food and assisting in its deglutition;
but in these it is by far the largest organ of the mouth, which when
closed it entirely conceals; and it not only retains but actually
seizes the animal's prey, by means of a very singular pair of jaws
with which it is furnished. Conceive your under-lip (to have recourse,
as Reaumur on another occasion[268], to such comparison,) to be horny
instead of fleshy, and to be elongated perpendicularly downwards[269],
so as to wrap over your chin and extend to its bottom,--that this
elongation is there expanded into a triangular convex plate[270],
attached to it by a joint[271], so as to bend upwards again and fold
over the face as high as the nose, concealing not only the chin and the
first-mentioned elongation, but the mouth and part of the cheeks[272]:
conceive, moreover, that to the end of this last-mentioned plate are
fixed two other convex ones, so broad as to cover the whole nose and
temples[273],--that these can open at pleasure, transversely like a
pair of jaws, so as to expose the nose and mouth, and that their inner
edges where they meet are cut into numerous sharp teeth or spines,
or armed with one or more long and sharp claws[274]:--you will then
have as accurate an idea as my powers of description can give, of the
strange conformation of the under-lip in the larvæ of the tribes of
_Libellulina_; which conceals the mouth and face precisely as I have
supposed a similar construction of your lip would do yours. You will
probably admit that your own visage would present an appearance not
very engaging while concealed by such a mask; but it would strike
still more awe into the spectators, were they to see you first open
the two upper jaw-like plates, which would project from each temple
like the blinders of a horse; and next, having by means of the joint
at your chin let down the whole apparatus and uncovered your face,
employ them in seizing any food that presented itself, and conveying
it to your mouth. Yet this procedure is that adopted by the larvæ
provided with this strange organ. While it is at rest, it applies
close to and covers the face. When the insects would make use of it,
they unfold it like an arm, catch the prey at which they aim by means
of the mandibuliform plates, and then partly refold it so as to hold
the prey to the mouth in a convenient position for the operation of
the two pairs of jaws with which they are provided. Reaumur once found
one of them thus holding and devouring a large tadpole;--a sufficient
proof that Swammerdam was greatly deceived in imagining earth to be
the food of animals so tremendously armed and fitted for carnivorous
purposes. Such an under-lip as I have described is found in the tribe
of dragon-flies (_Libellulina_); varied, however, considerably in its
figure in the different genera. In the larva of _Libellula_ Fab.,
such as _Libellula depressa_, &c. it is of the shape above described;
so exactly resembling a mask, that if Entomologists ever went to
masquerades, they could not more effectually relieve the insipidity of
such amusements and attract the attention of the _demoiselles_, than
by appearing at the supper table with a _mask_ of this construction,
and serving themselves by its assistance. It would be difficult, to
be sure, by mechanism to supply the place of the muscles with which
in the insect it is amply provided: but Merlin, or his successor, has
surmounted greater obstacles. In the larva of the Fabrician _Æshnæ_
(_Libellula grandis_, &c. L.), this apparatus is not convex but flat:
so that, though it equally conceals the face, it does not so accurately
resemble a mask; and the jaws at its apex are not convex plates, but
rather two single conical teeth[275]. It is, as to its general shape,
similarly constructed in _Agrion_ Fab. (_L. Virgo_, &c. L.); but the
first joint is more remarkably elongated, the jaws more precisely
resemble jaws than in any of the rest, and are armed with three long,
very sharp teeth: between them also there is a lozenge-shaped opening,
through which, when the apparatus is closed, is protruded a circular
sort of nipple, apparently analogous to the ligula[276]. _Libellula
ænea_, L., which is the type of another tribe (_Cordulia_ Leach), has a
mask somewhat different from all the above, the jaws being armed with
a moveable claw and an internal tooth[277]. You will admire the wisdom
of this admirable contrivance, when you reflect that these larvæ are
not fitted to pursue their prey with rapidity, like most predaceous
animals; but that they steal upon them, as De Geer observes[278], as
a cat does upon a bird, very slowly, and as if they counted their
steps; and then, by a sudden evolution of this machine, take them as
it were by surprise, when they think themselves safe. De Geer says, it
is very difficult for other insects to elude their attacks, and that
he has even seen them devour very small fishes[279]. As these animals
are found in almost every ditch, you will doubtless lose no time in
examining for yourself an instance of so singular a construction.
_Feelers_ (PALPI). In the orders _Diptera_ and _Hymenoptera_ are
many larvæ in which these organs have not been certainly discovered;
yet Reaumur in that of a common fly (_M. meridiana_ L.) found four
retractile nipples[280] which seem analogous to them; and Latreille
has observed, that below the mandibles of those of ants are four
minute points, two on each side[281]: but in all other larvæ their
existence is more clearly ascertained. The _maxillary_ palpi vary
in _number_, many having _two_ on each maxilla and others only
_one_. In the perfect insect the former is one of the distinguishing
characters of the predaceous beetles (_Entomophagi_ Latr.), but in
the larvæ it is more widely extended; since even in the caterpillars
of _Lepidoptera_ the inner lobe of the maxilla which represents this
feeler is jointed, which is precisely the case with the beetles
just named. Cuvier has observed this circumstance in the larva of
the stag-beetle[282]; and it belongs to many other _Coleoptera_
that have only a pair of maxillary palpi in the perfect state. The
_labial_ palpi are always two, emerging usually one on each side from
the apex of the under-lip. With regard to the _form_ of the palpi,
those of the _Lepidoptera_ are mostly conical; in other orders they
are sometimes setaceous and sometimes filiform. Their termination
is generally simple, but sometimes the last joint is divided. They
are for the most part very short, and the labial shorter than the
maxillary. The latter never exceed _four_ joints[283], which seems
the most natural number; and the former are limited to _three_. Both
vary between these numbers, and _one_ joint. The joints, though
commonly simple, are sometimes branched. This is the case with one I
met with in considerable numbers upon the Turnip, in October 1808,
the second joint of the palpi of which sends forth near the apex an
internal branch. In the larva of the _Cossus_, as Lyonnet informs
us[284], the joints of the palpi are retractile, so that the whole of
the organ may be nearly withdrawn.
* * * * *
After thus describing the _head_ of larvæ, and its principal organs,
we must next say something upon the remainder of the body, or what
constitutes the
2. _Trunk and Abdomen_: which I shall consider under one article.
These are composed of several _segments_ or rings, to which the
feet and other appendages of the body are fixed. The form of these
segments, or that of their vertical section, varies considerably: in
many _Lepidoptera_, the wire-worm, &c., it would be nearly circular;
in others a greater or less segment of a circle would represent it;
and in some, perhaps, it would consist of two such segments applied
together. Their lower surface is generally nearly plane. Their most
natural _number_, without the head and including the anal segment, is
twelve: this they seldom exceed, and perhaps never fourteen. The three
first segments are those which represent the _trunk_ of the perfect
insect, and to which the six anterior legs when present are affixed. In
general, they differ from the remaining segments only in being shorter,
and in many cases less distinctly characterized; but in Neuropterous
larvæ, those of _Dytisci_, and some other _Coleoptera_, they are longer
than the succeeding ones, and pretty nearly resemble the trunk of the
animal in its last state. The surface of the trunk and abdomen will be
considered under a subsequent head; I shall not, therefore, describe it
here. The _conformation_ of the different segments varies but little,
except of the terminal one, or tail, which in different larvæ takes
various figures. In most, this part is obtuse and rounded; in others
acute or acuminate; in others truncate; and in others emarginate, or
with a wider sinus, and with intermediate modifications of shape which
it would be endless to particularize. In some, also, it is simple and
unarmed; in others beset with horns, spines, radii, and tubercles of
different forms, some of which will come under future consideration.
The parts connected with the trunk and abdomen which will require
separate consideration, are the _legs_, the _spiracles_, and various
_appendages_.
_Legs._ It may be stated generally that the larvæ of the orders
_Coleoptera_, _Lepidoptera_, and _Neuroptera_, have legs; and that
those of the orders _Hymenoptera_ and _Diptera_ have none. This must
be understood, however, with some exceptions. Thus the larvæ of some
_Coleoptera_, as the weevil tribes (_Curculio_ L.) have no legs,
unless we may call by that name certain fleshy tubercles besmeared
with gluten, which assist them in their motions[285]; while those
of _Tenthredo_ and _Sirex_ in the order _Hymenoptera_ are furnished
with these organs. At present I know no Dipterous larva that may be
said to have _real_ legs, unless we are to regard as such certain
tentacula formed upon a different model from the legs of other
larvæ[286]. Rösel has, I think, figured a Lepidopterous apode. No
Neuropterous one has yet been discovered.
The legs of larvæ are of two kinds; either horny and composed of
joints, or fleshy and without joints[287]. The first of these, as
I observed in a former letter[288], are the principal instruments
of locomotion, and the last are to be regarded chiefly as props and
stays by which the animal keeps its long body from trailing, or by
which it takes hold of surfaces; while the other legs, or where there
are none, the annuli of its body, regulate its motions. The former
have been commonly called _true legs_ (_pedes veri_), because they
are persistent, being found in the perfect insect as well as in the
larva; and the latter _spurious legs_ (_pedes spurii_), because they
are caducous, being found in the larva only. Instead of these not
very appropriate names, I shall employ for the former the simple term
_legs_, and for the latter _prolegs_ (_propedes_)[289].
The legs, when present, are always in number _six_, and attached by
pairs to the underside of the three first segments of the trunk. They
are of a horny substance, and consist usually of the same parts as
those of the perfect insect; namely, _coxa_, _trochanter_, _femur_,
_tibia_, and _tarsus_, suspended to each other by membranous ligaments:
these parts are less distinctly marked in some than in others. Thus in
the legs of a caterpillar, or the grub of a capricorn-beetle, at first
you would think there were only three or four joints besides the claw;
but upon a nearer inspection, you would discover at the base of the
leg the rudiments of two others[290], in the latter represented indeed
by the fleshy protuberance from which the legs emerge. In the larvæ of
the predaceous _Coleoptera_, the hip and trochanter are as conspicuous
nearly as in the perfect insect; and the tarsus, which still consists
of only a single joint, is armed with two claws[291]. In those of the
_Neuroptera_ order, in which all the joints are very conspicuous, the
tarsi are jointed, as well as two-clawed[292]. The legs of larvæ are
usually shorter than those of the perfect insect, and scarcely differ
from each other in shape, for they all gradually decrease in diameter
from the base to the apex. This is the most usual conformation of
them in Lepidopterous, Hymenopterous, and some Coleopterous larvæ,
(those of the capricorn-beetles are very short and minute, so as to be
scarcely visible,) in which they are so small as to be concealed by the
body of the insect[293]. In Neuropterous larvæ, however, and several
_Coleoptera_, as those of _Dytiscus_, _Staphylinus_, _Coccinella_, &c.,
they more resemble the legs of the perfect insect, the joints being
more elongated, and the femoral one projecting beyond the body[294].
You will find no other than true legs in most Coleopterous,
Neuropterous, and Hymenopterous larvæ. But those of the saw-flies
(_Tenthredo_ L.), and all caterpillars, have besides a number of
_prolegs_: a few Dipterous larvæ also, are provided with some organs
nearly analogous to them. These _prolegs_ are fleshy, commonly
conical or cylindrical, and sometimes retractile protuberances,
usually attached by pairs to the underside of that part of the body
that represents the abdomen of the future fly[295]. They vary in
conformation and in number; some having but one, others as many as
eighteen.
With regard to their _conformation_, they may be divided into two
principal sections: first, those furnished with terminal claws; and
secondly, those deprived of them. Each of which may be divided into
smaller sections, founded on the general figure of the prolegs, and
arrangement of the claws or hooks.
i. The prolegs of almost all Lepidopterous larvæ are furnished
with a set of minute slender horny hooks, crotchets, or _claws_,
of different lengths, somewhat resembling fish-hooks; which either
partially or wholly surround the apex like a pallisade. By means
of these claws, of which there are from forty to sixty in each
proleg, a short and a long one arranged alternately, the insect is
enabled to cling to smooth surfaces, to grasp the smallest twigs to
which the legs could not possibly adhere: a circumstance which the
flexible nature of the prolegs greatly facilitates[296]. Claws nearly
similar are found on the prolegs of some _Dipterous_ larvæ[297],
but not in any of those of the other orders. These last, however,
are seldom either so numerous, or arranged in the same manner, as
in caterpillars. When the sole of the foot is open, the claws with
which it is more or less surrounded are turned outwards, and are in a
situation to lay hold of any surface; but when the animal wishes to
let go its hold, it begins to draw in the skin of the sole, and in
proportion as this is retracted, the claws turn their points inwards,
so as not to impede its motion[298].
The prolegs with claws may be further divided into four different kinds.
1. In the larvæ of the great majority of butterflies and moths they
assume the form of a truncated cone, the lower and smaller end of which
is expanded into a semicircular or subtriangular plate, having the
inner half of its circumference beset with the claws above mentioned;
and, from its great power of dilating and contracting, admirably
adapted for performing the offices of a foot. Jungius calls these legs
_pedes elephantini_[299]; and the term is not altogether inapplicable,
since they exhibit considerable resemblance to the clumsy but
accommodating leg and foot of the gigantic animal he alludes to.
2. The larvæ of many minute moths, particularly of the Fabrician
genera _Tortrix_ and _Tinea_--those which live in convoluted leaves,
the interior of fruits, &c., as well as the _Cossus_, and some
other large moths,--have their prolegs of a form not very unlike
those of the preceding class, but shorter, and without any terminal
expansion; the apex, moreover, is wholly, instead of half, surrounded
with claws[300]; the additional provision of which, together with a
centrical kind of nipple capable of being protruded or retracted,
in some measure, though imperfectly, supplies the place of the more
flexible plate-like expansion present in the first class.
3. The third class is composed of a very few _Lepidopterous_ larvæ
which have their prolegs very thick and conical at the base, but
afterwards remarkably slender, long, and cylindrical, so as exactly to
assume the shape of a wooden leg[301]. These, as in the first class,
are expanded at the end into a flat plate: but this is wholly circular,
is surrounded with claws, and has also in the middle a retractile
nipple, as in the preceding class. In _Cossus_, at least in an American
species (_Cossus Robiniæ_), described by Professor Peck[302], the anal
prolegs have the claws only on their _exterior_ half.
4. The remaining description of unguiferous prolegs, if they may
not rather be deemed a kind of tentacula, are those of certain
_Diptera_, provided with no true legs; which differ from the three
preceding classes, either in their shape, or the arrangement of their
claws. In one kind of those remarkable larvæ, which from their long
respiratory anal tubes Reaumur denominates "_rat-tailed_," that of
_Elophilus pendulus_, there are fourteen of these prolegs, affixed
by pairs to the ventral segments, the twelve posterior ones of which
are subconical, and truncate at the apex, which is surrounded with
two circles of very minute claws, those of the inner being much more
numerous and shorter than those of the exterior circle; while the
anterior pair terminate in a flat expansion, and in shape almost
exactly resemble those of a mole[303]. The prolegs of the larvæ of
a kind of gnat called by De Geer _Tipula amphibia_, and of _Syrphus
mystaceus_ F., (_Musca plumata_ De Geer,) are nearly of a similar
construction, but in the last are armed with three claws only[304].
Long moveable claws also distinguish the singular prolegs before
described[305] of another gnat (_Tanypus maculatus_ Meig., _Tipula_
De Geer). The case-worms (_Trichoptera_ K.) and some others, have two
prolegs at the anus, each furnished with a single claw[306].
ii. The prolegs _deprived_ of _claws_ are found in the larva of the
Hymenopterous tribe of saw-flies (_Tenthredo_ L.), in those of some
_Lepidoptera_ (_Hepialus_ F. &c.), and in some few Coleopterous and
Dipterous genera. Those of the former are of the shape of a truncated
cone, and resemble the second class of unguiculate prolegs, except
in the defect of claws. In the latter they are a mere retractile
nipple-like protuberance, in some species so small as scarcely to be
perceptible. In all they aid in progressive motion; but it is by laying
hold of surfaces, and so enabling the body more readily to push itself
forward by annular contraction and dilatation, and not by taking steps,
of which all prolegs are incapable: to assist in this purpose the
protuberance sometimes secretes a gluten[307], which supplies the place
of claws. Some larvæ have the power of voluntarily dilating certain
portions of the underside of their body, so as to assume nearly the
shape and to perform the functions of prolegs. In a Coleopterous (?)
subcortical one from Brazil, before alluded to, there are four round
and nearly flat areas in each ventral segment of the abdomen, but the
last very little raised above the surface, and rough, somewhat like a
file; and besides these, the base of the anal segment has ten of these
little rough spaces, but of a different shape, being nearly linear,
placed in a double series, five on each side. Doubtless these may be
regarded as a kind of _prolegs_, which enable the animal to push
itself along between the bark and the wood[308].
In considering, in the next place, the _number_ and _situation_ of
the prolegs, it will contribute to distinctness to advert to these
circumstances as they occur in the different orders furnished with
these organs.
To begin with the _Lepidoptera_.--Lepidopterous larvæ have either
ten, eight, six, or two prolegs, seldom more[309], and never fewer.
Of these, with a very few exceptions, two are attached to the last
or anal, and the rest, when present, to one or more of the _sixth_,
_seventh_, _eighth_, and _ninth_ segments of the body: none are ever
found on the fourth, fifth, tenth, or eleventh segments.
1. Where _ten_ prolegs are present, as is the case in by far the
greatest proportion of Lepidopterous larvæ, there is constantly an
anal pair, and a pair on each of the four intermediate segments just
mentioned.
2. In caterpillars, which like those of a few species of the genera
_Sphinx_, _Pyralis_, and of the _Bombycidæ_, &c. have _eight_ legs,
they are placed in _three_ different ways. In those which have an
anal pair, the remaining six are in some fixed to the sixth, seventh,
and eighth; in others, to the seventh, eighth, and ninth segments. In
those which, like _Cerura Vinula_, and several other species of the
same family, have no anal prolegs; the whole eight emerge from the
sixth, seventh, eighth, and ninth segments.
3. The Hemigeometers, as _Noctua Gamma_, &c. have only _six_ legs:
namely, an anal pair, and two ventral ones, situated on the eighth
and ninth segments.
4. The larvæ of the Geometers (_Geometræ_ F.) have but _four_
prolegs; of which two are anal, and two spring from the ninth
segment. It should be observed, however, that the larvæ of
Hemigeometers, and even of some of those that have ten prolegs, where
the four anterior ones are much shorter than the rest, move in the
same way as the Geometers. This even prevails in a few where these
organs are all of equal length.
5. Many of the larvæ of _Tinea_ L. which live in the interior of
fruits, seeds, &c., have but _one_ pair of prolegs, which are
attached to the anal segment.
6. The larvæ of Haworth's genus _Apoda_ (_Hepialus Testudo_
and _Asellus_ F.), remarkable for their slug-like shape and
appearance, move by the aid of two lateral longitudinal pustule-like
protuberances, which leave a trace of a gummy slime in their course.
_Hymenoptera._--The larvæ of the different tribes of _Tenthredo_ L.,
almost the only Hymenopterous insects in which prolegs are present,
have a variable number of these organs; some sixteen, as the saw-fly
of the willow (_T. lutea_ L.), and this is the most numerous tribe
of them, including the modern genera, _Cimbex_ F., _Pterophorus_,
&c. Others have fourteen, as that of the cherry (_T. cerasi_ L.);
and many others with only nine joints to their antennæ. A third
class have only twelve, as that of the rose (_T. Rosæ_ L.), but
this contains but few species. The last class contains those that
have no prolegs at all, but only the six horny ones appended to the
trunk. Of this tribe, the caterpillars of which have a very different
aspect from the preceding, are those of the genus _Lyda_ F. (_T.
crythrocephala_ L.)[310]. Two of the prolegs are anal, and the rest
intermediate, and none are furnished with claws. This circumstance,
in conjunction with the greater number of prolegs, except in the
case of _Lyda_, will always serve as a mark to distinguish these
_fausses chenilles_, as the French call the larvæ of saw-flies, from
true _caterpillars_. The _dorsal_ prolegs of a species of _Cynips_
described by Reaumur have been before noticed.
_Coleoptera._--The larvæ of insects of this order are so little known
or attended to, that no very accurate generalization of them in this
respect is practicable. Many of them, in addition to their six horny
legs, have a proleg at the anus; which in many cases appears to be
the last segment of the abdomen, forming an obtuse angle with the
remainder of it, so as to support that part of the body, and prevent
it from trailing; and in some instances, as in _Chrysomela Populi_,
a common beetle, secreting a slimy matter to fix itself[311]. In the
larvæ of _Staphylinidæ_ this proleg is very long and cylindrical;
in that of _Cicindela_ it is shorter, and in shape a truncated cone
rather compressed; it is very short, also, in those of the _Silphæ_
that I have seen. In the wire-worm (_Elater Segetum_) it is a minute
retractile tubercle, placed in a nearly semicircular space, shut
in by the last _dorsal_ segment, which becomes also ventral at the
anus. This space is in fact the last ventral segment. This seems
characteristic of the genus[312]. From the underside of the body of
the common meal-worm (_Tenebrio Molitor_), at the junction of the two
last segments, when the animal walks, there issues a fleshy part,
furnished below with two rather hard, long, and moveable pediform
pieces, which the animal uses in walking[313]. In the larva of
another beetle, whose ravages have been before noticed, under the
name of the cadelle[314] (_Trogosita mauritanica_), a pair of prolegs
are said to be found under the anal segment; and in that of the
bloody-nose beetle (_Timarcha tenebricosa_), that segment is bifid.
That of the weevil of the common water-hemlock (_Lixus paraplecticus_
F.) exhibits a singular anomaly: prolegs occupy the usual station
of the true legs, being attached to the three segments representing
the trunk[315]. This insect, however, does not appear to use them
in moving. A pair in each of the twelve segments of the body are
found in the grub of another weevil (_Hypera Rumicis_ Germ.), the
nine last pair being the shortest, which all assist the insect in
walking[316]. But the greatest number of prolegs is to be found in
the Brazil subcortical larva lately mentioned. Besides the six horny
legs of the trunk, this remarkable animal has four prolegs on each
of the seven intermediate abdominal segments, and five on each side
of the base of the last, making the whole number of prolegs, if so
they may be called, amount to forty-four: a far greater number than
is to be found in any larva at present known. When I wrote to you
upon the motions of insects, I informed you that some larvæ moved
by means of legs upon their back[317], but I was not then aware that
any were furnished with them both on the back and the belly at the
same time. By the kindness of Mr. Joseph Sparshall of Norwich, a very
ardent and indefatigable entomologist, I am in possession of the
larva of _Rhagium fasciatum_, a timber-feeding beetle. This animal
on the ten intermediate segments of the underside of the body, which
in the centre form a fleshy protuberance, has on it a double series
of rasps, as it were, consisting each of two rows of oblique oblong
prominences; and on the seven intermediate _dorsal_ segments there
are also in the centre seven rasps of three or four rows each, of
similar prominences: so that this animal at the same time can push
itself along both by dorsal and ventral prolegs. It is worthy of
observation, that a pair of these rasps is between the second and
third pair of true legs.
_Diptera._--The larva of a little gnat, _Tipula stercoraria_ De
Geer[318] (_Chironomus_ Meig.?), drags itself along by the assistance
of a _single_ tubercle, placed on the underside of the first
segment of the body, which the animal has the power of lengthening
or contracting[319]. That of another beautiful _Chironomus_ (_C.
plumosus_), remarkable for the feathered antennæ of the male[320],
has _two_ short prolegs, or pediform but not retractile tentacula in
the same situation[321]. Others, as that of _Tanypus maculatus_,
&c. have _two pairs_, one attached to the anal and the other to the
first segment[322]. _Tipula amphibia_ De Geer in this state has _ten_
prolegs, placed by pairs on the fourth, fifth, eighth, ninth, and
tenth _dorsal_ segments[323]; and _Scæva Pyrastri_ F., one of the
aphidivorous flies, has not fewer than _forty-two_, arranged in a
sextuple series, seven in each row[324].
It may not be useless to close this long description of the _legs_ of
larvæ with a tabular view of them, founded chiefly upon these organs;
which afford very obvious marks of distinction.
I. Larvæ without legs.
i. With a corneous head of determinate shape (coleopterous and
hymenopterous _apods_--_Culicidæ_, some _Tipulidæ_, &c.
amongst the _Diptera_).
ii. With a membranaceous head of indeterminate shape (_Muscidæ_,
_Syrphidæ_, and other _Diptera_).
II. Larvæ with legs.
i. With legs only, and with or without an anal proleg
(_Neuroptera_, and many _Coleoptera_).
1. Joints short and conical (_Elater_, _Cerambycidæ_,
&c.).
2. Joints long and subfiliform (_Staphylinus_,
_Coccinella_, _Cicindela_, &c.).