bees--and there is no reason to think that other insects do not
follow the same law--is in or near the _mouth_, and above the
proboscis. It remains, therefore, that we endeavour to discover
its _precise_ situation: and as insects cannot tell us, nor can
we perceive by their actions, in what precise part the sense in
question resides, the only modes to which we can have recourse to
form any probable conjecture, are analogy and dissection. At first,
the opinion noticed above, that the palpi are its organs, seems not
altogether unreasonable; but as the argument from analogy, except
as to their situation near the mouth, is not in favour of them, and
there seems no call, were smell their function, for the numerous
variations observable in their structure, I think we must consider
them, as I have endeavoured to prove, rather as instruments of
touch. Let us now inquire, whether there be not discoverable upon
dissection, in the interior of the head of any insects, some organ
that may be deemed, from its situation, under what we have called
the nose and nostrils, the seat of the sense we are treating of.
The common burying-beetle (_Necrophorus Vespillo_) is an insect
remarkable for its acuteness of smell, which enables it to scent
out and bury, as was formerly related to you[1067], the carcases of
small animals. Take one of these insects, and kill it as formerly
directed,--examine first its nose: in the middle of the anterior part
you will see a subtrapezoidal space, as it were cut out and filled
with a paler piece of a softer and more membranous texture. Next
divide the head horizontally; and under the nose, and partly under
this space, which I call the _rhinarium_ or nostril-piece[1068], you
will find a pair of circular pulpy cushions, covered by a membrane
transversely striated with beautifully fine striæ. _These_ are what
I take to be the organs of smell, and they still remain distinctly
visible in a specimen I have had by me more than fifteen years.
A similar organ may be discovered in the common water-beetle
(_Dytiscus marginalis_), but with this peculiarity, that it is
furnished with a pair of _nipples_. I have before described an
analogous part covered with papillæ, in _Æshna viatica_, and you
will find it in other insects[1069]. Perhaps at first this part
may seem merely a continuation of the palate; but if you consider
the peculiarities in its structure just noticed, it is evidently
a sensiferous organ; and as the sense of smell appears to reside
in the head, this is its most probable seat. But by what channel
scents act upon it,--whether they are transmitted through the pores
of the part representing the nostrils, or received by the mouth,--I
will not venture to assert positively: but from the circumstance
of their being _membranous_ in some insects remarkable for acute
scent, as in _Necrophorus_, _Staphylinus_, &c., there seems some
ground for the _former_ opinion, which receives further confirmation
from an observation of an eminent Comparative Anatomist, M. Carus,
with respect to _Acrida verrucivora_, in which under the _nose_ and
_rhinarium_, as appears from his description, he found some tracheæ,
and two lobes of the cerebral ganglion, which caused him to regard
this as the seat of the sense of smell[1070]. He also tells us that
Rosenthal, in the blue-bottle-fly (_Musca vomitoria_) places the
sense of smell partly in a delicately folded membrane observable
in its head[1071]. As the sense of smell in these little beings
is extremely acute, as well as their hearing, the perception of
odours may reach their sensory through the above pores; and even
those in the hard rhinarium of an _Anoplognathus_ may receive and
transmit them; and besides the upper-lip and nose are often united
by membrane, perhaps representing the _rhinarium_, as in _Goerius_,
&c.[1072] which may facilitate such transmission.
* * * * *
That insects _taste_, no one hesitates to believe, though some have
supposed the palpi to be the organ of that sense; but as they have
a _tongue_, as we have shown, we may with Cuvier conclude, that one
of its primary functions is to _taste_ their food[1073]. I shall not
therefore launch out further upon this head.
I have now placed before you a picture, or rather sketch, of the
insect world. And whether we regard their general history and
economy, their singular metamorphoses, the infinite varieties and
multiplicity of their structure both external and internal, and
their diversified organs both of sense and motion--I think you will
be disposed to own, that in no part of his works is the hand of an
ALMIGHTY and ALL-WISE CREATOR more visibly displayed, than in these
minutiæ of creation; that they are equally worthy of the attention
and study of the Christian Philosopher with any of the higher
departments of the animal kingdom; and that all praise is due to Him,
for placing before our eyes, for our entertainment and instruction,
such a beautiful moving picture of little symbols and agents,
perpetually reflecting his glory and working his will.
I am, &c.
FOOTNOTES:
[1025] VOL. III. p. 15. note^a.
[1026] Ibid. 58--. See above, p. 26.
[1027] _N. Dict. d'Hist. Nat._ xxx. 584.
[1028] _Hor. Entomolog._ 37.
[1029] _N. Dict. d'Hist. Nat._ xxx. 584--.
[1030] Cuv. _Anat. Comp._ ii. 362.
[1031] _Syst. Nat._ i. 535. Bonnet _Œuvr._ ii. 36.
[1032] _Ibid._
[1033] VOL. II. p. 162.
[1034] Lehmann _De Sens. Extern. Animal. Exsang._ 22--.
[1035] _Ibid._ _De Antenn. Insect._ ii. 79.
[1036] VOL. III. p. 43--.
[1037] See above, p. 1--.
[1038] VOL. III. p. 46.
[1039] _De Antenn. Insect._ ii. 65--.
[1040] _De Antenn. Insect._ ii. 42.
[1041] _Ibid._ 26.
[1042] See above, p. 218.
[1043] VOL. II. p. 64, 198--.
[1044] VOL. III. p. 319--.
[1045] _Philos. Trans._ 1820. 314.
[1046] Lehmann _De Usu Antenn._ ii. 66--.
[1047] VOL. I. p. 48, 110.
[1048] Compare what is said above (p. 141) with respect to bees.
[1049] See, for further arguments, Lehmann _ubi supr._ c. ix.
[1050] Marcel de Serres thinks he has discovered an organ of hearing
in most insects, but he does not state its situation. _Mém. du Mus._
1819. 99. Treviranus, with regard to the _Blattina_, suspects it to
be situated between the eye and the base of the antennæ, perhaps
alluding to the spot noticed above. (VOL. III. p. 505.) Carus, who
mentions the above, says, "Is it not reasonable to ask if the sense
of hearing may not reside in the membrane which connects the antennæ
with the head?" _Introd. to Comp. Anat._ i. 80--.
[1051] Lehmann _De Sens. Extern. Anim. Exsang._ De Olfactu.
[1052] Cuv. _Anat. Comp._ ii. 675.
[1053] _Ubi supr._
[1054] Marcel de Serres says they are connected with _testes_ seated
in the trunk (_Mem. du Mus._ 1819. 95); but Treviranus denies this
(_Arachnid._ 36--. _t._ iv. _f._ 33).
[1055] VOL. II. p. 361--. III. p. 544--.
[1056] Lehmann _De Sens. Extern. &c._ De Olfactu.
[1057] Lehmann _ubi supr._ &c. 27.
[1058] _Ibid._ and _De Usu Antenn._ ii. 24--. Cuv. _Anat. Comp._ ii.
675.
[1059] Lehmann _De Usu Antenn._ ii. 28.
[1060] _Ibid._ 31.
[1061] _Ibid._ 35--.
[1062] VOL. III. p. 475--.
[1063] _N. Dict. d'Hist. Nat._ xxiii. 210.
[1064] _Ubi supr._
[1065] See above, p. 63. Sprengel _Commentar._ 14--.
[1066] Huber _Abeilles_ ii. 375--. Dr. Bevan in his interesting work
on the _Honey-Bee_ adopts the opinion here stated with respect to the
organ of smell in that animal. 265, 303.
[1067] VOL. I. p. 352--.
[1068] VOL. III. p. 480--.
[1069] VOL. III. p. 454--.
[1070] _Introd. to Comp. Anat._ i. 76. The part he alludes to, is
figured PLATE VI. FIG. 4. a. g´.
[1071] _Ibid._ This membrane likewise represents the Nose and
Rhinarium in that fly.
[1072] VOL. III. p. 481.
[1073] Cuv. _Anat. Comp._ ii. 682--.
LETTER XLVI.
_ORISMOLOGY, OR EXPLANATION OF
TERMS._
It was by the language of _terms_ that he invented and employed, as
well as by his system and methods of arrangement, that Linné smoothed
the way to the study of Natural History;--having therefore led you
through a large portion of the _flowery_ fields of the Science of
Entomology, I must now conduct you into that _arid_ but not barren
or unprofitable region. To enable you to understand descriptions of
insects, or to describe them yourself, you must have a knowledge of
the _technical_ language by which their parts and characters are
expressed. Much of this you already know from the definitions of
external parts, furnished in a former letter[1074]: I shall now give
you a more full and general explanation of terms, adding many new
ones for unnoticed characters, that may be conveniently employed.
The science of terms, which I shall call _Orismology_[1075], may be
divided into _two_ branches--_General_ Orismology, and _Partial_
Orismology; the first containing _general_ definitions, and the last
those relating to _particular_ parts and organs.
A. GENERAL ORISMOLOGY.
I. SUBSTANCE.
1. MEMBRANOUS (_Membranacea_). A fine, thin, transparent
substance. A _Membrane_.--Ex. _Wings_ of _Hymenoptera_ and
_Diptera_.
2. PERGAMENEOUS (_Pergamenea_). A thin, tough, and less
transparent substance, somewhat resembling _parchment_.--Ex.
The _Tegmina_ of the _Orthoptera_[1076].
3. CORIACEOUS (_Coriacea_). A thicker, flexible substance,
resembling _leather_.--Ex. _Elytra_ of _Telephorus_ and the
_Malacodermi_.
4. CORNEOUS (_Cornea_). A hard inflexible substance resembling
_horn_.--Ex. _Elytra_ of _Lucanus Cervus_ and many other
_Coleoptera_.
5. CRUSTACEOUS (_Crustacea_). A rigid calcareous substance.--Ex.
The _Shell_ of a _Lobster_ or _Crab_.
6. CALLOUS (_Callosa_). A substance without pores, harder than
the surrounding matter, and usually elevated above it.--Ex.
Elevated parts of the _Collar_ in _Nomada_. (_Mon. Ap. Angl._
Apis * b.)[1077] Spots on the _elytra_ of _Stenocorus_
(_Tylostagmus_ K. MS.) _bimaculatus_ and affinities.
7. CARTILAGINEOUS (_Cartilaginea_). A gristly substance between
bone and ligament.--Ex. The _Tongue_ of many _Hymenoptera_.
8. SUBEREOUS (_Suberea_). A soft elastic substance somewhat
resembling _cork_[1078]. The _galls_ of some species of
_Cynips_ when mature approach to this substance.
9. SPONGIOSE (_Spongiosa_). A soft elastic substance resembling
_sponge_.--Ex. The _Pulvilli_ of _Thanasimus_, _Buprestis_, &c.
10. LIGNEOUS (_Lignosa_). A hard unelastic substance like
_wood_.--Ex. _Galls_ of some species of _Cynips_.
11. CARNOSE (_Carnosa_). A soft, _fleshy_ substance.--Ex.
_Caterpillars_ and _Grubs_.
12. TUBULOSE (_Tubulosa_). When the interior is _hollow_ or empty.
13. SOLID (_Solida_). When the interior is _full_.
II. RESISTANCE.
1. RIGID (_Rigida_). Hard, which does not bend or yield to
pressure.--Ex. The weevils (_Rhyncophora_).
2. FLEXILE (_Flexilis_). Which easily bends, or yields to pressure
without breaking.--Ex. _Elytra_ of _Telephorus_.
3. SOFT (_Mollis_). Flexile and retaining the marks of
pressure.--Ex. _Elytra_ of _Meloe_.
III. DENSITY.
1. FOLIACEOUS (_Foliacea_). Very thin and depressed, scarcely
thicker than a leaf.--Ex. _Aradus corticalis_ and _Coreus
paradoxus_.
2. DEPRESSED (_Depressa_). When the _vertical_ section is shorter
than the _transverse_.--Ex. _Trogosita mauritanica_.
3. COMPRESSED (_Compressa_). When the _transverse_ section is
shorter than the _vertical_.--Ex. _Centrotus cornutus_:
_Abdomen_ in _Cynips_.
4. PLUMP (_Pinguis_). Naturally and proportionably plump.--Ex.
_Thylacites_, &c. Most of the _Cicadæ_.
5. OBESE (_Obesa_). Unnaturally enlarged and distended, as if
from disease or too much food. Ex. _Chrysomela Polygoni_ ♀,
_Galeruca Tanaceti_ ♀, _Brachycerus_.
6. VENTRICOSE (_Ventricosa_). Bellying out as if filled with
air.--Ex. _Pneumora_.
IV. PROPORTION.
1. THICK (_Crassa_). Disproportionably thick throughout.--Ex.
_Copris_.
2. INCRASSATE (_Incrassata_). Disproportionably thick in
part.--Ex. _Base_ of the _Abdomen_ of _Æshna_ and many
_Libellulina_. PLATE IX. FIG. 9.
3. SLENDER (_Tenuis_). Disproportionably slender throughout.--Ex.
_Lixus paraplecticus_.
4. ATTENUATE (_Attenuata_). Disproportionably slender in
part.--Ex. _Tail_ of _Scorpio_, _Raphidia_ ♂, &c.
5. BROAD (_Lata_). Disproportionably broad throughout.
6. DILATATE (_Dilatata_). Disproportionably broad in part.--Ex.
_Elytra_ of _Lycus fasciatus_, &c. PLATE XIII. FIG. 20.
7. NARROW (_Angusta_). Disproportionably narrow throughout.--Ex.
_Abdomen_ of _Agrion_.
8. ANGUSTATE (_Angustata_). Disproportionably narrow in part.--Ex.
_Elytra_ of _Sitaris humeralis_. PLATE XIII. FIG. 19.
9. LONG (_Longa_). Disproportionably long throughout.--Ex.
_Scolopendra_.
10. ELONGATE (_Elongata_). Disproportionably long in part.--Ex.
_Abdomen_ of _Libellulina_.
11. SHORT (_Brevis_). Disproportionably short throughout.--Ex.
_Copris_.
12. ABBREVIATE (_Abbreviata_). Disproportionably short in
part.--Ex. _Elytra_ of _Staphylinidæ_, _Atractocerus_, &c.
V. FIGURE[1079].
1. CIRCULAR (_Circularis_). Having the diameter every way equal.
PLATE XXIX. FIG. 16, 17.
2. ROTUNDATE (_Rotundata_). Rounded at the angles or sides. PLATE
XXIX. FIG. 19.
3. OVAL (_Ovalis_). Having the _longitudinal_ diameter _twice_ the
length of the _transverse_, and the ends circumscribed by equal
segments of a circle. PLATE XX. FIG. 6.
4. ELLIPTIC (_Elliptica_). Oval, but having the _longitudinal_
diameter _more_ than _twice_ the length of the _transverse_.
PLATE XX. FIG. 19.
5. OBLONG (_Oblonga_). Having the _longitudinal_ diameter _more_
than _twice_ the length of the _transverse_, and the ends
varying, or rounded. PLATE XX. FIG. 3, 9.
6. OVATE (_Ovata_). Oval, but having the ends circumscribed by
unequal segments of circles. PLATE XX. FIG. 12, 13.
7. CORDATE (_Cordata_). Heart-shaped. Ovate or subovate and
hollowed out at the base, without posterior angles. PLATE IX.
FIG. 22.
8. SAGITTATE (_Sagittata_). Arrow-shaped. Triangular, hollowed out
at the base with posterior angles. PLATE XXVII. FIG. 41. _w´´´_.
9. HASTATE (_Hastata_). Halberd-shaped. Triangular, hollowed out
at the base and sides with the posterior angles spreading.--Ex.
_Horn_ of the _prothorax_ of _Dynastes hastatus_. _Postfurca_
in many _Coleoptera_. PLATE XXII. FIG. 5. _b_ †.
10. TRIANGULAR; QUADRANGULAR; QUINQUANGULAR; SEXANGULAR
(_Triangula_; _Quadrangula_; _Quinquangula_; _Sexangula_).
Having _three_, _four_, _five_, or _six_ angles.
11. TURBINATE (_Turbinata_). Top-shaped, triangular with curved
sides. PLATE XXV. FIG. 18.
12. ENSATE (_Ensata_). Gradually tapering till it ends in a
point.--Ex. _Ovipositor_ of _Acrida viridissima_. PLATE XV.
FIG. 19.
13. LANCEOLATE (_Lanceolata_). Oblong and gradually tapering
towards each extremity.--Ex. The _Cerci_ in _Blatta_. PLATE XV.
FIG. 23. _Q´´_.
14. SIGMOIDAL (_Sigmoidea_). S-shaped. Lanceolate and concave
on one side at the base, and on the other at the apex.--Ex.
_Ovipositor_ of _Cimbex_, PLATE XV. FIG. 21. _H´´_.
15. CUNEATE (_Cuneata_). Wedge-shaped. Having the _longitudinal_
diameter exceeding the _transverse_, and narrowing gradually
downwards. PLATE X. FIG. 11.
16. ACINACICATE (_Acinacicata_). Falchion-shaped. Curved with
the apex truncate, and growing gradually wider towards
the end.--Ex. _Abdomen_ of _Ophion_, _Fœnus_, and other
_Ichneumonidæ_[1080].
17. LUNULATE (_Lunulata_). Crescent-shaped. Curved with both ends
acute, like the moon in her first quarter.--Ex. _Last_ joint of
the _labial palpi_ of _Oxyporus_. PLATE XIII. FIG. 4. _a._
18. FALCATE (_Falcata_). Sickle-shaped. Curved with the apex
acute.--Ex. _Ovipositor_ of _Acrida varia_. _Antennæ_ of
_Atractocerus_. PLATE XI. FIG. 8.
19. LINEAR (_Linearis_). Narrow and of the same width
throughout.--Ex. _Wings_ of _Pterophorus monodactylus_.
20. ARCUATE (_Arcuata_). Linear and bent like a bow.--Ex. _Rostrum_
of _Balaninus Nucum_. PLATE XIII. FIG. 12.
21. CULTRATE (_Cultrata_). Coulter-shaped. Straight on one side and
curved on the other.--Ex. _Ovipositor_ of some _Saw-flies_.
_Under-wing_ of many _Ichneumonidæ_.
22. SPATULATE (_Spatulata_). Spatula-shaped. Broader and rounded at
the _apex_, linear and narrow at the _base_.--Ex. _Abdomen_ of
_Ichneumon amictorius_ Panz.
23. CLEPSYDRATE (_Clepsydrata_). Hour-glass-shaped. Broader at the
base and apex--Ex. The _Prosternum_ of many Capricorn beetles.
24. CLAVATE (_Clavata_). Club-shaped. Linear at the _base_, but
towards the _apex_ growing gradually broader. PLATE XI. FIG. 4.
25. QUADRATE (_Quadrata_). Square. Quadrilateral with the sides
_equal_ and the angles _right_ angles.
26. RHOMBOID (_Rhomboidea_). Quadrilateral with the sides equal,
but with two opposite angles _acute_, and two _obtuse_. PLATE
XXVII. FIG. 62. _t´´_.
27. TRAPEZATE (_Trapezata_). Quadrilateral with the _four_ sides
unequal, and none of them perfectly parallel. PLATE XIV. FIG. 4.
28. TRAPEZOID (_Trapezoidea_). Quadrilateral, with _two_ sides
unequal and parallel[1081]. PLATE XXVI. FIG. 34. b´.
29. PARALLELOGRAMICAL (_Parallelogramica_). Quadrilateral, with
_all_ the angles right angles, and _all_ the sides parallel,
but two longer than the others.
VI. FORM[1082].
1. SPHERICAL (_Sphærica_). The shape of a _globe_. A body whose
diameter every way is equal. PLATE XX. FIG. 5.
2. ORBICULATE (_Orbiculata_). A depressed globe, whose
_horizontal_ section is circular, and _vertical_ oval. PLATE
XX. FIG. 10, 11.
3. LENTICULAR (_Lenticularis_). Lens-shaped. Whose _horizontal_
section is circular, and _vertical_ lanceolate.--Ex. _Abdomen_
of _Cynips aptera_.
4. OVALIFORM (_Ovaliformis_). Whose _longitudinal_ section is
oval, and _transverse_ circular. PLATE XX. FIG. 6.
5. ELLIPSOID (_Ellipsoidea_). Whose _longitudinal_ section is
elliptical, and _transverse_ circular. PLATE XX. FIG. 19.
6. OVIFORM (_Oviformis_). Whose _longitudinal_ section is ovate,
and _transverse_ circular. PLATE XX. FIG. 12, 13.
7. CUCUMIFORM (_Cucumiformis_). Cucumber-shaped. Whose
_longitudinal_ section is oblong, and _transverse_ circular.
PLATE XX. FIG. 18, excluding the _neck_.
8. CORDIFORM (_Cordiformis_). Oviform and hollowed out at the base
without posterior angles. PLATE IX. FIG. 22.
9. CONICAL (_Conica_). Whose _vertical_ section is triangular, and
_horizontal_ circular.--Ex. _Abdomen_ of _Cœlioxys conica_
(_Apis_ * * b. K.). PLATE XX. FIG. 7.
10. TURBINIFORM (_Turbiniformis_). Whose _vertical_ section
is turbinate, and _horizontal_ circular.--Ex. _Joints_ of
_antennæ_ of _Aleochara socialis_, and many others of that
genus.
11. PYRAMIDAL (_Pyramidalis_). Whose _vertical_ section is
triangular, and _horizontal_ quadrangular.
12. CUNEIFORM (_Cuneiformis_). Whose _vertical_ section is cuneate,
and _horizontal_ parallelogramical.
13. TRIQUETROUS (_Triquetra_). Whose _horizontal_ sections are
equilateral triangles. PLATE XI. FIG. 6.
14. ENSIFORM (_Ensiformis_). Whose _horizontal_ sections are
_acute_-angled triangles gradually _diminishing_ in diameter
from the base to the apex, and propagated in a _straight_ line.
PLATE XI. FIG. 7.
15. ACINACIFORM (_Acinaciformis_). Whose _horizontal_ sections are
_acute_-angled triangles gradually _increasing_ in diameter
from the base to the apex, and propagated in a _curved_ line.
16. CULTRIFORM (_Cultriformis_). Whose _horizontal_ sections are
equal acute-angled triangles, or a three-sided body with two
equal sides large and the third small.
17. DELTOID (_Deltoidea_). Short with the horizontal section
triangular and decreasing in diameter towards the base.--Ex.
_Apex_ of the _posterior tibia_ in _Copris lunaris_.
18. TRIGONAL; TETRAGONAL; PENTAGONAL; HEXAGONAL; POLYGONAL
(_Trigona_; _Tetragona_; _Pentagona_; _Hexagona_; _Polygona_).
Whose horizontal section is triangular; quadrangular;
quinquangular; sexangular; multiangular.
19. TRIEDRAL; TETRAEDRAL; PENTAEDRAL; HEXAEDRAL; POLYEDRAL
(_Triedra_; _Tetraedra_; _Pentaedra_; _Hexaedra_; _Polyedra_).
That hath _three_ sides; _four_ sides; _five_ sides; _six_
sides; _many_ sides.
20. PRISMOIDAL (_Prismoidalis_). Having more than _four_ sides and
whose _horizontal_ section is a polygon[1083]. PLATE VI. FIG.
13. _a, b,_ d´.
21. TRAPEZIFORM (_Trapeziformis_). Whose _horizontal_ section is a
_Trapezium_.
22. TRAPEZOIDIFORM (_Trapezoidiformis_). Whose _horizontal_ section
is trapezoid.
23. RHOMBIFORM (_Rhombiformis_). Whose _horizontal_ section is
rhomboidal. PLATE VIII. FIG. 11.
24. TWO-EDGED (_Anceps_). Whose _horizontal_ section is lanceolate.
25. CYLINDRICAL (_Cylindrica_). Whose _horizontal_ sections are all
equal circles. PLATE XXI. FIG. 4.
26. FUSIFORM (_Fusiformis_). Spindle-shaped. Whose _vertical_
section is lanceolate or lineari-lanceolate, and _horizontal_
circular. PLATE XXIII. FIG. 12.
27. COLUMNAR (_Teres_). Whose _vertical_ section is cuneate, and
_horizontal_ circular. PLATE XVI. FIG. 2, 3.
28. CLAVIFORM (_Claviformis_). Whose _vertical_ section is clavate,
and _horizontal_ circular. PLATE XI. XII. FIG. 4.
29. CUBICAL (_Cubica_). _Six_-sided, with sides quadrate.
30. PARALLELOPIPEDOUS (_Parallelopipeda_). _Six_-sided, with _four_
parallelogramical and _two_ quadrate sides.
31. PYRIFORM (_Pyriformis_). Pear-shaped. Whose _vertical_ section
is spatulate, and _horizontal_ circular.--Ex. _Apion_, &c.
32. INFUNDIBULIFORM (_Infundibuliformis_). Funnel-shaped. Whose
_horizontal_ sections are circular, at first equal and then
progressively larger and larger. PLATE XXII. FIG. 12. c.
33. FORNICATE (_Fornicata_). Convex above and concave beneath.
PLATE XIII. FIG. 18. _a._
34. COARCTATE (_Coarctata_). When the diameter of the _middle_
is less than that of the _ends_.--Ex. _Posterior thigh_ of
_Locusta_. PLATE XIV. FIG. 5.
35. CALCEOLIFORM (_Calceoliformis_). Oblong, and somewhat coarctate
in the middle.--Ex. _Abdomen_ of _Chelonus_.
36. LAGENIFORM (_Lageniformis_). Bellying out and then ending in a
narrow neck, something like a _bottle_.--Ex. _Sperm-reservoir_
attached to the oviduct in _Pontia_. PLATE XXX. FIG. 12. _d._
37. CONSTRICT (_Constricta_). Suddenly and disproportionably
smaller at one end. PLATE XXII. FIG. 15.
38. LUNIFORM (_Luniformis_). Whose longitudinal section is lunate.
PLATE XIII. FIG. 4.
39. NODOSE (_Nodosa_). Having one or more knobs or swellings. PLATE
XII. FIG. 5.
40. GENICULATE (_Geniculata_). Bent so as to form a knee or angle.
PLATE XII. FIG. 7.
VII. SUPERFICIES.
i. PARTS.
1. DISK (_Discus_). The middle of a surface.
2. LIMB (_Limbus_). The circumference.
3. MARGIN (_Margo_). The extreme sides.
4. APEX (_Apex_). The summit.
5. BASE (_Basis_). The bottom.
6. SUPINE SURFACE (_Pagina superior_). The _upper_ surface.
7. PRONE SURFACE (_Pagina inferior_). The _under_ surface.
ii. ELEVATION AND DEPRESSION.
1. NAVICULAR (_Navicularis_). When two sides meet and form an
angle like the _outer_ bottom of a _boat_.--Ex. _Notonecta
glauca_.
2. CONVEX (_Convexa_). An elevation the arc of which _is_ the
segment of a circle.--Ex. _Upper_ Surface of the body of most
_Coleoptera_.
3. GIBBOUS (_Gibba_). An elevation the arc of which is _not_ the
segment of a circle[1084].--Ex. _Shoulders_ of the _elytra_ of
_Prionus coriarius_, and of many other _Coleoptera_.
4. PLANE (_Plana_). Flat. When the disk is not higher than the
limb, nor the limb than the disk.
5. CONCAVE (_Concava_). A depression the arc of which _is_ the
segment of a circle.
6. EXCAVATE (_Excavata_). A depression the arc of which is _not_
the segment of a circle.--Ex. _Prothorax_ of _Sinodendrum
cylindricum_.
iii. SCULPTURE.
1. EQUATE[1085] (_Æquata_). Without _larger_ partial elevations or
depressions.
2. SMOOTH (_Lævis_). Without _smaller_ partial elevations or
depressions.
3. LEVIGATE (_Lævigata_). Without _any_ partial elevations or
depressions.
4. PORE (_Porus_). A minute impression that _perforates_ the
substance.
5. POROSE (_Porosa_). Beset with many pores.--Ex. _Elytra_ of most
_Apions_.
6. A POINT (_Punctum_). A minute impression upon the surface, but
_not perforating_ it.
7. PUNCTATE (_Punctata_). Beset with many points.--Ex. Impression
on the _Head_ and _Prothorax_ of _Phyllopertha Horticola_, &c.
8. VARIOLE (_Variola_). A shallow impression like a mark of the
small-pox.
9. VARIOLOUS (_Variolosa_). Beset with many varioles.--Ex.
_Scarabæus variolosus_.
10. UMBILICATE (_Umbilicata_). When a variole, tubercle, granule,
&c. has a _depression_ in its centre.--Ex. _Thorax_ of
_Pachygaster scabrosus_.
11. FOVEOLET (_Foveola_). A roundish and rather deep depression,
larger than a variole.
12. FOVEOLATE (_Foveolata_). Having one or more foveolets.--Ex.
_Prothorax_ of _Geotrupes stercorarius_.
13. FOSSULET (_Fossula_). A somewhat long and narrow depression.