831 
ENTOMOLOGY. 
are extended when the infefli flies, and (hut when it reds, 
forming a longitudinal future down ,the middle of the 
back ; they are of various (hapes, and diffinguifhed by the 
following names :— Abbreviate, when fliorter than the ab¬ 
domen. Truncate, when their extremities terminate in a 
tranfverfe direbt line. Fafligiate, when of equal or greater 
length than the abdomen, and terminating in a tranfverfe 
line. Serrate, or toothed , having their external margins 
edged with teeth or notches. Spifiofe, when their exterior 
furfaces are covered with fmall (harp points. Scabrous, 
when very rough. Striate , when marked with (lender 
longitudinal furrows. Porcate, having (harp longitudinal 
ridges. Sulcate, with deep furrows. They are likewife 
diffinguifhed by the denomination of hemelytra, when their 
cafes are neither fo hard as the elytra, nor fo delicate as 
the tranfpar.ent wings. 
Under the wings of mod infebts which have only two, 
there is a fmall head placed on a dalk, frequently under 
t a little arched fcale ; thefe are called halteres, or poifers ; 
they appear to be rudiments of tire hinder wings: it lias 
been (uppofed that they ferve to keep the body in equili- 
brio when the infedt is flying. 
The elytra, or exterior cafes, are much harder and 
more opake than the wings under them ; they are gene¬ 
rally highly polifhed, and often enriched with various 
colours, adorned with ornamental flu tings, and dudded 
with brilliants, wliofe beauties are beyond defeription. 
All thefe ornaments are united in the curculio imperialis, 
or diamond beetle, one of the riched and mod magnificent 
creatures in nature; the head, the wings, the legs, &c. 
are curioufly befet with feales of a mod fplendid appear¬ 
ance, outvying the ruby, faphire, and emerald, forming, 
under the microfcope, one of the mod noble phenomena 
that the colours of light can exhibit. It is faid, that in 
the Brazils, from whence they come, it isalmofi impoffi- 
ble to look at them on a funny day, when they are flying 
in little fwarms, fo great is the glowing fpl'endewrof their 
heightened colours. For the figure and natural hidory of 
it, fee the article Curculio, vol. v. p.480. 
The ftrength and hardnefs of the elytra are admirably 
adapted to the various purpofes of the infects to which 
they are appropriated ; at the fame time that they protect 
the tender wings beneath them, they ferve as a (hield to 
the body ; while the ribs, and other prominences, contri¬ 
bute to leffen the fribtion and diminiffi the preffure to 
which they are often expofed. In mod of thefe infebts, 
the under wing is longer and larger than the exterior 
fhell, fo that it is obliged to be bent and folded up, in or¬ 
der to lie under the elytra ; for this purpofe they are fur- 
nifhed with drong mufcles, and proper articulations to dif- 
play or conceal them at pleafure. The united drength and 
fplendour of the elytra may be pleadingly contemplated by 
referring to that noble infebt the cerambyx giganteus, exhi¬ 
bited in the engravingoppofite Cerambyx, vol. iv. p. 34. 
The wings of moths and butterflies are moflly imbricate 
or farinaceous, being covered wdth a fine dud, which ren¬ 
ders them opake, and produces thofe beautiful and varie¬ 
gated colours by which they are fo richly adorned, and 
fo profufely decked. If this be wiped off, we find the 
naked wing to conlid of a number of ribs, like thofe in 
the leaves of plants, but of a crudaceous nature ; the 
larged rib runs along and fortifies the exterior edge of the 
wing ; the interior edge is drengthened by a fmaller veffel 
or rib. The ribs are all hollow, by which means the 
wing, though comparatively large, is very light. The 
The membrane between the ribs, which conffitutes the 
body of the wing, is furprifingly thin and tranfparent; and 
as this is extremely tender, one life of the feales may be 
to protect it from injuries. When the moth emerges from 
the chryfalis, the wings are (oft and thick, and it they be 
examined in that date, Will be found to confid of two 
membranes, that may be railed up and feparated, by 
blowing between them with a fmall tube : the ribs lie be¬ 
tween thefe membranes. With the aflidance of glalfes 
we dilcover certain drait and circular rows of extremely 
minute holes, running from rib to rib, or forming figures 
in the intermediate fpaces, which feem to anfwer to 
the figures and variegations on the complete wing, and 
are probably the fockets for the flalks or (terns of the 
fmall feales. 
Legs.— Thefe are found to vary greatly in different 
infebts. The mod general number is fix ; many of the 
clafs aptera have eight, as the fpider ; the hornet has ten ; 
the onifeus or wood-loufe fourteen ; the julus has from 
feventy to one hundred and twenty on each fide. The 
legs of thofe infebts that have not more than ten, are 
affixed to the trunk, while thofe that exceed that num¬ 
ber, have part fixed to the trunk, the red to the abdo¬ 
men. The legs of infebts are divided into four parts. 
The firfl, which is ufually the larged, and connebted to 
the body, is called the femur ; the fecond, or tibia, is 
joined to the former, and is commonly of the fame fize 
throughout, and longer than the femur; this is followed 
by the third part, which is didinguifhed by the name of 
tarjiis, or foot ; it is compofed of feveral joints, the one 
articulated to the other, the number of rings varying in 
different infebts; the tarfus is terminated by the unguis, 
or claw. 
Entomologids, in order to render their deferiptions 
clear and accurate, have given feveral names to the legs 
of infebts, from the nature of the motions produced by 
them. Thus curforii, from that of running; thefe are the 
mod numerous. The faltatorii , thofe that are ufed for 
leaping; the thighs of thefe are remarkably large, by 
which means they poffefs confiderable drength and power 
to leap to great didances; as the grafshopper. The naia- 
torii, thofe that ferve as oars for fwimming; the feet of 
thefe are flat, and edged with hairs, polfeffing a proper 
furface to ftrike againd the water, as in the dytifeus, 
notonebta, &c. Such feet as have no claws are termed 
mutici. The chelee, or claws, are an enlargement of the 
extremity of the fore feet, each of which is furniflied 
with two leffer claws, which abt like a thumb and finger, 
as in the crab ; and are called chelate. The under part of 
the feet in fonte infebts is covered with a kind of brufli or 
fponge, by which they are enabled to walk with eafe, on 
the mod polidied fubdances, fuel! as panes of glafs, in 
every direbtion. 
Many infeds can only move the thigh in a vertical di¬ 
redion, while others can move it in a variety of ways. 
The progreflive motion of infeds, and the various me¬ 
thods employed to effed it, will be found a very curious 
and important fubjed, and well worthy the attention of 
the naturalid. The intelligent mechanic may not find it 
lod labour if he bedow fome time on the fame fubjed. 
Very little has been done on this head, and that princi¬ 
pally by Reaumur, in his excellent Memoires ;. and by 
M. Weifs, in a Memoir publifhed in the Journal de Phy- 
fique for 1771. The reader may alfo confult Borelli de 
Motu Animalium. 
Cauda, the tail, terminates the abdomen, and is con- 
druded in a wonderful manner for arifwering the pur¬ 
pofes for which it is formed, namely, to dired the motion 
of the infed, to ferve as an indrument of defence, or for 
depofiting its eggs; tire figure and fize thereof varying in 
each genus and its fpecies, and rnolily different in the 
male and female, and thus ferving to diltinguifli the fexes. 
In mod inleds it is Ample, and yet capable of being ex-' 
tended or drawn back at pleafure; in others elongated, 
as in the crab and fcorpion ; or fliaped like a bridle, as 
in thp raphidia ; or with three appendages like bridles, 
as in the ephemera ; in fome it is forked, as in the po- 
dura; and in others it is furniflied with a pair of forceps, 
as in the earwig; in the blatta, grylli, and others, it is 
foliofe, or like a leaf; in tlie fcorpion and panorpa it is 
furniflied with a dart or ding. 
Aculeus, the (ting, is an indrument with which infebts 
wound and inffil a poifon; the ding generally proceeds 
from the under part of the lad ring of the belly; in fome 
it is Iharp and pointed, in others ferrated, or formed like a 
jCavv a 
