of the scorpion are replaced by pseudo-spiracles; these in _Epeira
Diadema_ are three pair of small black points: on the back of the
abdomen also are _four_ pair, but in some species there are only
_two_[2169]: the most remarkable, however, are exhibited by the
cancriform spiders before noticed[2170]: in _Epeira cancriformis_, in
the plate which covers the abdomen, they are dark red spots with an
elevated rim and centre[2171] exactly resembling spiracles, except
that they are not perforated; there are twenty-four of them, twenty
arranged round the margin, and four in a square in the disk.
3. _Organs of motion._ In a former letter you were told that several
insects are enabled to leap by means of _organs_ in their abdomen;
I shall now describe such of them as require further elucidation. I
then said that _Podura_ and _Sminthurus_, two apterous genera, take
their leaps by means of an anal _fork_[2172]. In the former genus the
fork consists of a single piece attached to the under side of the
anus, and terminating in a pair of long slender sharp processes which
articulate with it and form the fork or saltatorious instrument[2173].
In _Sminthurus_ the _tines_, as they may be called, of the fork do not
articulate with the base, but are of the same piece and consist of two
joints, the terminal one being flat and obtuse[2174]. _Machilis_ to
the anal fork adds eight pair of ventral linear springs (_Elastes_),
which are covered with hair or scales, and terminate in a bristle or
two. I have on a former occasion mentioned the natatorious laminæ with
which the anus of the larva of _Agrion_ and of some _Diptera_ is
furnished[2175]; the same part in that of _Dytiscus_ ends in a pair
of tapering organs, fringed on each side like the hind-legs of the
imago[2176], which doubtless assist it in swimming; those respiratory
foliaceous laminæ which so singularly distinguish the abdomen of the
larvæ of _Ephemera_, like the legs of the Branchiopod _Crustacea_, are
probably used in some degree as fins, and aid their motions in the
water[2177]. Under this head may also be mentioned the many-jointed
bristles that form the long tails[2178] of the fly that proceeds from
these larvæ, whose interesting history I long since enlarged upon; for
when they fly the two lateral ones diverge from the central one, and
perhaps perform the same office as the tail feathers (_rectrices_) of
birds. These bristles are also to be found in _Machilis_[2179], and
probably, as its _leaps_ are almost as long as _flights_, for a similar
purpose, to steady their motion. I may here lastly state that I once
saw a _Cryptophagus_ (_Corticaria_ Marsh.), but I forgot to note the
species, walking upon my window, which when it wanted to turn fixed
itself to the glass by an inflated anal vesicle, and so accomplished
its purpose.
4. _Organs of Prehension_[2180]. The abdominal organs of _prehension_
are various; but as the great body of them are connected with the
sexual intercourse of insects, I shall not consider them till I come
to treat on that subject. The only remarkable one that is common to
both sexes is that of the earwig, which is too well known to every
child to call for any long description. The external organs of
_oviposition_ I shall also describe hereafter, and likewise those of
_secretion_ that have not already been noticed.
5. _Weapons._ As the _stings_ of some _Hymenoptera_ are analogous to
the _ovipositors_ of the majority of that Order, I shall consider
them both together when I treat of the sexual organs of insects;
but there is one, and that a tremendous one, not connected with
those organs, which may be noticed here. I mean the sting of the
_scorpion_. There appears to be some analogy between the poisonous
fangs of one tribe of the Ophidian reptiles[2181], the mandibulæ
of spiders[2182], the second pair of pedipalps, or the fangs of
the _Scolopendridæ_[2183], and the organ in question[2184]; but
the last possesses this peculiarity, that it is placed at the
opposite extremity of the body, where it is preceded by a long
jointed tail, which properly speaking is merely a continuation of
the abdomen, since the spinal marrow, the intestinal canal, and the
_pseudocardia_, are extended into it[2185]. Providence might have a
double view in thus contracting the dimensions of this part of the
abdomen; in the first place, the animal is by this enabled to turn
its tail over its back preparatory to its inflicting a wound, and
in the second, perhaps, this formation favours the sublimation of
the venom, the long tail acting as an alembic for that purpose. This
machine consists of six angular joints including the sting, the last
but one being the longest, and the last inflated, as it were, at the
base, and terminating in a sharp subulato-conical point which curves
downwards, and has an orifice in a channel at the end on each side.
Treviranus could not discover these orifices in the sting of _Scorpio
europæus_[2186]; they may however be readily seen if viewed with a
sufficiently high power, though not under a common pocket microscope.
Whether the very slender, many-jointed, _real_ tail of the remarkable
genus _Thelyphonus_ is used in any respect as a _weapon_, has not
been ascertained: it is a filiform hairy organ consisting in some
specimens of more than _twenty_ joints, the first being very much
larger than the rest[2187].
6. _Appendages_[2188]. We are lastly to advert to those _appendages_
of the abdomen of which the use is not at present discovered.
These are the styles (_styli_) of the _Staphylinidæ_; the leaflets
(_foliola_) of the _Libellulina_; the floret (_flosculus_) of the
_Fulgoræ_; the _cerci_ of the _Blattidæ_ and _Gryllina_; and the
threads (_fila_) of _Machilis_: but having nothing important to add
concerning them, the definitions of those terms will give you a
sufficiently clear idea of them[2189]. As they are common to both
sexes, if their use is connected with the sexual intercourse, it
must be similar to that which Treviranus ascribes to the pectens of
scorpions, they must be instruments of excitement.
* * * * *
And now, after this long discourse on the External Anatomy and
structure of these little beings, you may think perhaps at first
that the subject is exhausted; and that I must have discovered and
described every part and every variation of every part of the crust
of an insect. But when you go on to reflect what a comparatively
small number of these creatures have fallen under my examination,
and in those, after all my laborious and painful researches, from
my limited faculties and other imperfections of our common nature,
how much will probably have eluded my notice, you may conclude that
thousands of facts still remain concealed to reward the patient
assiduity of future investigators. Such are the immensity and variety
of the works of the CREATOR in this department, that it would require
a long life, and fill volumes upon volumes, to discover and give a
description of all the peculiarities of structure of the insects that
are already known; and could all that exist[2190] be so studied and
explained in full detail, the library that the Calif Omar ordered to
be burned at Alexandria could scarcely have contained more books than
would be required to receive the results. But "who is sufficient for
these things[2191]?" This is a question that the most able and most
experienced physiologist must often feel disposed to put to himself
when, lost in the intricate labyrinth of the works of his Maker, he
sees all things arranged, "wheel within wheel," in an order that
he can only _partially_ unravel, instead of tracing the "regular
confusion" through all its windings. But glimpses of light, and
points of irradiation, here and there discover to _fragments_ of the
truth of things, and such vestiges of the grand system of the DEITY,
as enable him in some degree to appreciate, and dispose him humbly to
adore that WISDOM, POWER, and GOODNESS, that at first created and now
sustains in its full beauty and harmony the WONDROUS WHOLE.
I am, &c.
END OF THE THIRD VOLUME.
Printed by Richard Taylor,
Shoe-Lane, London.
[Illustration: _Plate VI._]
[Illustration: _Plate VII._]
FOOTNOTES:
[2125] _Anatom. Compar._ i. 450.
[2126] _Anatom. Compar._ i. 451.
[2127] De Geer notices something of the kind in _Cimbex femorata_.
ii. 947.
[2128] It was omitted to be observed, when the supposed pneumatic
pouches in the genus _Vespa_ were mentioned (see above, p. 585), that
they have also a very conspicuous metaphragm, as probably have most
_Hymenoptera_, to which the muscles that move the wings are attached.
[2129] PLATE IX. FIG. 13. _F´_ is the tendon, G´ the aperture in the
abdomen C, and a, the aperture in the trunk B.
[2130] PLATE XV. FIG. 11. _Linn. Trans._ xii. _t._ xxii. _f._ 16.
[2131] Surely these _Epeiræ_, of so different a habit from the rest,
form a distinct genus?
[2132] See above, p. 339.
[2133] There is reason to suppose that in _Chelonus_ and the _Chrysidæ_
several segments are retracted within the abdomen, and if the cavity of
its under side in the latter be examined, it will be discovered that
the _epigastrium_ is divided in the middle into two pieces, and that
both the sides of this and the following segments are covered by three
narrow accessory plates, one to each, the last being the shortest. De
Geer (ii. 833.) describes _Chrysis ignita_ as having _four_ abdominal
rings; but this is only in _appearance_, there being really only
_three_. This appearance is produced by the apex of the last dorsal
segment being more depressed and marked with several deep little
excavations that look like holes. In some species of _Stilbum_ this
segment consists as it were of three ridges or steps.
[2134] In this genus the ventral segments are replaced by a long
narrow central plate, succeeded by a minute one.
[2135] In this genus the bed of the posterior coxæ appears to consist
of two segments, which are beautifully fringed with parallel short
bristles.
[2136] _Anatom. Compar._ i. 451.
[2137] PLATE VIII. FIG. 9. _A´´_, _B´_.
[2138] Ibid. FIG. 5. _A´´._
[2139] PLATE XV. FIG. 10.
[2140] Reaum. v. _t._ xvii. _f._ 14. _a. a._
[2141] _Linn. Trans._ v. _t._ xii. _f._ 15.
[2142] Daldorf (_Asiatic Society's Trans._ vii.) has divided
_Geotrupes_ into two families, one with the podex _covered_ (_G.
vernalis_, &c.) which he calls _modesti_, the other with it
_uncovered_ (_G. stercorarius_, &c.) which he calls _obscæni_.
[2143] PLATE VIII. _E´._
[2144] Ibid. _D´._
[2145] _Sur le Vol des Ins._ c. i. Addend. 299.
[2146] In _Dytiscus marginalis_ the upper side of the margin of the
_Hypochondria_ is curiously cut into transverse corrugations.
[2147] PLATE VIII. FIG. 6. _C´._
[2148] Ibid. _B´´._
[2149] PLATE VIII. _L´._
[2150] _Linn. Trans._ xi. _t._ ix. _f._ 15. _b._
[2151] PLATE IX. FIG. 18. _I´._
[2152] Ibid. FIG. 17. _H´._
[2153] Rœmer. _Genera_, &c. _t._ xxiv. _f._ 4.
[2154] Stoll _Spectr._ _t._ vii.
[2155] PLATE XV. FIG. 10-23.
[2156] See above, p. 339--.
[2157] This tubercle I find only in a specimen from Sweden, sent
to me by Major Gyllenhal, but not in any British one I possess. In
this specimen the declivity before mentioned (see above, p. 709.) is
observable in the _first_ segment, but in the others it is formed by
the _second_.
[2158] See above, p. 617.
[2159] _Punaises_, _t._ xiii. _f._ 84.
[2160] Stoll _Punaises_, _t._ xiii. _f._ 101.
[2161] _Ibid._ _t._ xvii. _f._ 117.
[2162] _Ibid._ _t._ xxxvi. _f._ 253.
[2163] See above, p. 339--.
[2164] De Geer, vi. 260. _t._ xv. _f._ 8. _d._
[2165] PLATE XXIX.
[2166] PLATE XXIX. FIG. 22. is part of the back of the abdomen of the
pupa of a _Pentatoma_. _a_ the pseudo-spiracle, _b_ the connecting
corrugations.
[2167] Ibid. FIG. 24. _a._
[2168] Ibid. FIG. 27. _a._
[2169] Treviranus. _Arachnid._ 23--.
[2170] See above, p. 702, 706.
[2171] PLATE XXIX. FIG. 26. represents one of them.
[2172] VOL. II. p. 319--.
[2173] PLATE XV. FIG. 14. _M´´._ De Geer, vii. _t._ ii. _f._ 5, 10, 21.
[2174] Ibid. _t._ iii. _f._ 4, 14.
[2175] See above, p. 154.
[2176] PLATE XVIII. FIG. 5. _a._
[2177] PLATE XXIX. FIG. 3, 4. De Geer, ii. _t._ xvii. _f._ 12. and
_t._ xviii. _f._ 2.
[2178] Ibid. _t._ xvi. _f._ 8-13.
[2179] PLATE XV. FIG. 16. _S´´._
[2180] Ibid. FIG. 12. _L´´._
[2181] _Philos. Trans._ 1818. _t._ xxii.
[2182] _N. Dict. d'Hist. Nat._ ii. 275--. Hoole's _Leeuwenh._ i. _t._
ii. _f._ 19. I.
[2183] Leeuwenh. _Epist._ 17. Octobr. 1687. _f._ 10. C.
[2184] Hoole's _Leeuwenh_. i. _t._ v. _f._ 12, 13.
[2185] Treviranus, _Arach._ 4.
[2186] Treviranus, _ubi supr._ 14.
[2187] In my specimen including the first joint there are _twenty_,
and some seem to have been broken off. In Rœmer's figure (_Genera_,
_t._ xxix. _f._ 11.) there are only _ten_. Perhaps they vary in
number according to the age of the animal.
[2188] PLATE XV. FIG. 13, 16, 17.
[2189] See above, p. 391--.
[2190] I have heard it stated upon good authority that 40,000 species
of insects are already known, as preserved in collections. How great,
then, must be the number existing in this whole globe!
[2191] 2 Cor. ii. 16.
EXPLANATION OF THE PLATES[2192].
PLATE VI.[2193]
FIG.
1. Head of _Mylabris_. Upper side, or _face_.
2. ------------------- Under side, or _subface_.
3. Trophi of _Dytiscus_. _Six_ pieces.
4. Head of _Locusta_. Face.
5. ------------------ Front view, to exhibit the mouth.
6. Trophi of ditto. _Seven_ pieces.
7. Head of _Cicada_. Face.
8. ------- _Scutellera_. Subface.
9. Trophi, or _promuscis_ of _Hemiptera_. _Three_ pieces.
10. Head of _Æshna_. Face.
11. ---------------- Front view.
12. Trophi of ditto. _Seven_ pieces.
13. ------ or _antlia_ of _Lepidoptera_. _Four_ pieces.
14. ------ of _Panorpa_. _Three_ pieces.
PLATE VII.[2194]
FIG.
1. Head and trophi of _Phryganea_ L. Face.
2. ------------------ _Vespa Crabro_. Ditto.
3. Trophi of _Bombus_.
4. Head of _Tabanus_ L. Face.
5. Trophi or _proboscis_ of ditto. (Reaum.)
6. ------------------------ _Bombylius_[2195].
7. Head of _Oxypterum_. Face.
8. Head of _Pulex_, with its antennæ and trophi, or _rostrulum_.
Side view.
9. ------- _Araneidæ_, with the trunk.
10. Trophi of ditto.
11. Head of _Scolopendra morsitans_. Subface.
12. ---------------- --------------- Front view, to show the mouth.
13. Trophi of ditto.
14. Pharynx of _Pentatoma_. (Savigny.)
[Illustration: _Plate VIII._]
PLATE VIII.[2196]
FIG.
1. Prothorax of _Lucanus_. a. Apex. b. Base. c d. Sides. _a._ Disk.
2. Antepectus of ditto.
3. Alitrunk of ditto. Upper side. a. A piece between the
metathorax and metaphragm.
4. ------------------ Under side.
5. Abdomen. Upper side, or _tergum_.
6. -------- Under side, or _venter_.
7. Antepectus of _Hydrophilus piceus_.
8. Alitrunk of ditto. Under side, to show the metasternum.
9. Abdomen of _Dynastes Aloeus_, to show the dorsal and ventral
spiracles.
10. Prothorax of _Locusta_. a. Apex. b. Base, c c. Sides.
11. Antepectus of ditto, to show the prosternum.
12. Alitrunk of ditto. Upper side.
13. ------------------ Under side.
14. ------------------ Lateral view. VOL. III. p. 48.
15. Abdomen of ditto. Lateral view.
16. Alitrunk of _Cicada_ Latr. Upper side.
17. -------------------------- Under side. a. The piece in the ♀
corresponding to the drum-covers of the ♂.
18. Abdomen, and part of postpectus of ♂ ditto. Under side, to show
the drums. VOL. II. p. 405--.
19. Abdomen, and part of postpectus of ♂. Lateral view, with the
covers removed to show the machinery.
20. Alitrunk. Upper side. _Pentatoma_.
[Illustration: _Plate IX._]
PLATE IX.[2197]
FIG.
1. Alitrunk of _Cossus ligniperda_. Upper side.
2. Part of ditto, to show the mesophragm.
3. ------------- Under side.
4. Patagia of _Lepidoptera_. Upper and under sides. VOL. III. p.
368, 539.
5. Tegulæ of ditto. _Two_ species. VOL. III. p. 378.
6. Prothorax of _Æshna_. a. The base elevated and forming an
obtuse angle with the rest.
7. Alitrunk of ditto. Upper side. a. Two elevated areas of the
posterior parts of the collar, strengthened by a marginal ridge
and denticles, internally connected by an elastic ligament,
apparently to aid and sustain the powerful action of the
wing-muscles.
8. ------------------ Lateral view. a. A piece by which the
mid-leg is connected with the scapular. VOL. III. p. 48, 565.
9. Part of the abdomen of _Libellula_.
10. Trunk of _Semblis_ F. Upper side.
11. Alitrunk of _Vespa Crabro_. Upper side. a. Aperture in the
trunk for the passage of the ligament that elevates the abdomen.
12. Lateral view of ditto.
13. --------------- posterior part of ditto, and of the base of the
abdomen, to show the above apparatus. a. The aperture. VOL.
III. p. 701.
14. Head and part of the manitrunk of _Tenthredo_ L. to show the
membrane _a._ representing the prothorax. VOL. III. p. 550--.
15. Alitrunk of _Xiphydria_. Upper side.
16. ------------------------ Lateral view.
17. Part of trunk and abdomen of _Formica_, to show the _squama_.
VOL. III. p. 389. 3.
18. ------------------------- of _Myrmica_, to show the _nodus_.
VOL. III. p. 389. 4.
19. Alitrunk of _Musca_. Upper side. a. _Alula_ or winglet.
20. Metathorax of ditto.
21. Alitrunk of ditto. Lateral view.
22. Abdomen of ditto. Venter.
[Illustration: Plate X.]
PLATE. X.[2198]
N.B. In this plate the _red_ points out the _costal_, and
the _yellow_ the _anal_ areas, the _intermediate_ being
_uncoloured_.
FIG.
1. Elytra, a. Base. b. Shoulder. c. Lateral margin. d. Apex.
2. Tegmina. _Blatta_.
3. Hemelytra. _Pentatoma_.
4. Wing. _Coleoptera._ a. An insulated nervure. VOL. III. p. 625.
5. ----- _Dermaptera._
6. ----- _Lepidoptera._
7. ----- _Neuroptera._
8. ----- _Hymenoptera. Tenthredo_ L.
9. ------------------- _Bombus._
10. Under wing. _Hymenoptera._
11. --------------------------- _Proctotrupes._
12. ----------- _Diptera. Tipula._
13. --------------------- _Psychoda._ VOL. III. p. 645.
14. --------------------- _Musca._ a b. Two areolets between
the costal and mediastinal nervures. c. Areolet between the
mediastinal and postcostal nervures. d. Areolet between
the postcostal and subcostal nervures, e. Open areolet. VOL.
III. p. 634.
15. Under wing. _Diptera._ _Stratyomis._ a b. The two areolets
between the costal and postcostal nervures; the mediastinal
being nearly obsolete. c. Middle areolets crowned by a small
one, d.
[Illustration: Plate XI.]
[Illustration: Plate XII.]
PLATE XI.[2199] _Antennæ._
FIG.
1. Setaceous.
2. Capillary.
3. Filiform.
4. Incrassate.
5. Fusiform.
6. Prismatic.
7. Ensiform.
8. Falciform.
9. Moniliform.
10. Dentate.
11. Serrate.
12. Imbricate.
13. Distichous.
14. Pectinate.
15. Duplicato-pectinate.
16. Ciliate.
17. Flabellate.
18. Ramose.
19. Furcate.
20. Auriculate. _a._ The _auricle_.
21. Palmate.
22. Irregular.
23. Perfoliate.
PLATE XII. _Antennæ._
FIG.
1. Capillaceous.
2. Mucronate.
3. Uncinate.
4. Clavate.
5. Nodose, or Biclavate.
6. Convolute.
7. Geniculate.
8. Capitate with a tunicate knob.
9. Capitate with a solid knob.
10. Capitate with a perfoliate knob.
11. Filiform.
12. Globiferous.
13. Connate.
14. }
15. } Setigerous.
16. Subulate.
17. }
18. } Filate, simple.
19. Filate, compound. _a._ Joints.
20. Filate.
21. Aristate. Setarious _a._ Bristle.
22. Aristate. Plumate _a._ Bristle.
23. Stupeous. VOL. III. p. 646.
24. Plumose.
25. Scopiferous. _a._ Brush.
26. Barbate.
27. Verticillate.
28. Inflated.
29. Auriculate. _a._ Auricle.
PLATE XIII.[2200]
1. Unguiculate feeler. _Gonyleptes._ _a._ Claw.
2. Securiform ditto. _Cychrus._ _a._ Terminal joint.
3. Inflated ditto. _Araneidæ_ ♂. _a._ ditto.
4. Lunulate ditto. _Oxyporus._ _a._ ditto.
5. Dentate mandible. _Megachile._
6. Suctorious ditto. Larva of _Dytiscus_. _a._ Aperture.
7. Prosthecate ditto. _Staphylinus._ VOL. III. pp. 356, 439.
8. Trophi of _Curculio_ L.
9. Pedunculate eyes. _Diopsis._ _a._ Footstalk.
10. Compound ditto. _Muscidæ._ VOL. III. p. 494. 3.
11. Conglomerate ditto. _Iulus._ Ibid. p. 494. 2.
12. Rostrate head. _Balaninus._
13. Capistrate ditto. _Nitidula._
14. Clypeate ditto. _Copris._
15. Lychnidiate ditto. _Fulgora._
16. Buccate ditto. _Myops._ _a._ The inflated part.
17. Cruciate prothorax. _Locusta._
18. Cucullate and alate ditto. _Tingis._
19. Subulate elytra. _Sitaris._
20. Ampliate ditto. _Lycus._ #/
[Illustration: _Plate XIII._]
[Illustration: _Plate XIV._]
[Illustration: _Plate XV._]
PLATE XIV.[2201]
FIG.
1. Ideal wing, to exemplify painting. VOL. IV. p. 286--. a.
Anterior or exterior margin. b. Interior ditto. c. Posterior
ditto. d. Humeral angle. e. Scutellar ditto. f. Posterior
ditto. g. Anal ditto. _a._ Articulate _fascia_, or band.
_b._ Macular ditto. _c d._ Sesquialterous ditto. _d e._
Sesquitertious ditto. _f._ Dimidiate ditto. _g._ Abbreviate
ditto. _h._ Pyramidate ditto. _i._ Supercilium. _k._ Hastate
pupil. _l._ Compound eyelet or _ocellus_. _m._ Nictitant ditto.
_n._ Simple ditto. _o._ Annulet. _p._ Bipupillate eyelet. _q._
Sesquialterous ditto. _r._ Double ditto. _s._ Caudate wing.
_t._ Pupil. _u._ Iris. _v._ Atmosphere.
2. Reversed wings. _Gastrophaca._
3. Digitate ditto. _Pterodactylus._
4. Falcate ditto. _Attacus._
5. Saltatorious leg, with loricate thigh. _Locusta._
6. Natatorious ditto. _Dytiscus._
7. Ambulatorious ditto. _Lucanus._
8. Prehensorious ditto. _Gonyleptes._
PLATE XV.[2202]
FIG.
1. Laminate coxa. _Haliplus._
2. Alate tibia. _Lygæus phyllopus_, a. The appendage.
3. Clypeate ditto. _Crabro_ ♂. a. The clypeus. VOL. III. p. 334.
4. Dolabriform ditto. _Curculio maritimus_ E.B.
5. Fossorious leg, with palmate tibia. _Clivina._ VOL. II. p. 365.
6. --------------- with digitate ditto. _Gryllotalpa._ Ibid. p.
366.
7. Chelate feeler. _Scorpio._
8. Scutate tarsus. _Hydrophilus piceus_ ♂. VOL. III. p. 336.
9. Patellate ditto. _Dytiscus marginalis_ ♂. a. Cups. Ibid. p.
336, 694--.
10. Obumbrate _abdomen_. _Epeira cancriformis._
11. Retracted ditto. _Gonyleptes._
12. Cheliferous tail. _Panorpa_ ♂.
13. Flosculiferous ditto. _Fulgora._
14. Saltatorious ditto. _Podura._
15. Folioliferous ditto. _Æshna._
16. Cauduliferous, and filiferous ditto. _Machilis._
17. Styliferous ditto. _Staphylinus._
18. Unciferous ovipositor. _Locusta._
19. Ensate ditto. _Acrida._
20. Navicular ditto. _Cicada._
21. Serrulate ditto. _Tenthredo_ L.
22. Telescopiform ditto. _Chrysis._
23. Anal apparatus of _Blatta_.
[Illustration: _Plate XVI._]
PLATE XVI.[2203]
FIG.
1. Extricated ovipositor. _Pimpla._ _Two_ pieces.
2. Telescopiform ditto. _Stomoxys calcitrans?_ (Reaum.)
3. -------------------- _Œstrus._ (Ibid.) VOL. I. p. 150.
4. Semicomplete pupa. _Cicada._
5. Subsemicomplete ditto. _Libellula._ _a._ Mask. VOL. III. p.
125--.
6. Incomplete ditto. _Hydrophilus._ (Lyonnet.)
7. ----------------- _Myrmeleon_ emerging from its cocoon. (Reaum.)
8. ----------------- _Vespa vulgaris._
9. ----------------- _Chironomus plumosus._ (Reaum.) _a b._
Respiratory plumes.
10. Obtected pupa. _Apatura Iris._
11. -------------- _Vanessa Urticæ._ _a._ Head-case with _two_
points.
12. -------------- _Gonepteryx Rhamni._ _a._ Head-case with _one_
point.
13. Obtected pupa. _Sphinx Ligustri._ _a._ The tongue-case. _b._
The eye-case. _c._ The trunk-case. _d._ First segment of the
abdomen. _e._ The adminicula. _f._ The mucro, or point of the
tail. VOL. III. p. 249--.
14. Hairy obtected pupa of _Laria fascelina_.
[Illustration: _Plate XVII._]
[Illustration: _Plate XVIII._]
PLATE XVII.[2204]
FIG.
1. Coarctate pupa. _Œstrus hæmorrhoidalis._ (Reaum.)
2. --------------- _Stratyomis chamæleon._ (Ibid.) _a._ The pupa
as formed within the skin of the larva.
4. Oviform body which many pupæ of _Diptera_ at first assume under
the skin of the larva. (Ibid.). VOL. III. p. 235.
3. The same when the parts begin to show themselves. (Ibid.)
5. Cocoon of _Saturnia pavonia_. _a._ Pupa. _b._ Threads that
close the orifice. VOL. III. p. 217, 279.
6. Loose and irregular ditto, of _Arctia villica_. Ibid. p. 220.