The HISTORY of INSECTS; 
GH FA °P 
107 
V: 
Deferibes the external parts of the Ejfca or bait, its colour; and the difference ith 
: its manners and difpofition, 
AVING_ accurately examined the 
Worm of the Ephemerus, I obferve that 
it is divided into fourteen annular divifions; the 
firft conftitutes the head; the three fubfequent 
the thorax ; and the other ten the belly, with 
the tail annexed. 
In the head, Tab. XIII. fig. rv. 2, the eyes 
are very confpicuous, being invefted with a 
uniform and {mooth coat, and covered on either 
fide with briftly hairs. When the Worm is on 
the point of changing its old skin, we obferve 
this {mooth coat to part or feparate by degrees 
from its eyes, and the eyes when the little crea- 
ture begins to fly; appear reticular as they are 
in Flies. A little lower under the eyes are 
feen two tender horns 44, terminating in fharp 
points, and articulated or divided into joints. 
Under thefe are feen a pair of dentated forceps 
or jawsc, conftituting the creature’s mouth, 
About the origin of thefe jaws, underneath, 
feveral more hairy and membranous little parts 
appear, which are fomewhat like thefe that we 
obferve in Crabs and Shrimps. 
To the firft ring of the thorax are fixed the 
two fore legs d, the ftructure whereof, and the 
joints of which they confift, merit great notice. 
The ftructure is in fome meafure like that ob- 
ferved in creatures that borrow under the earth. 
Hence the ftrongeft motion which thefe legs 
have is outward, by which they can the more 
conveniently pierce and remove the earth, like 
Moles in making their cells. 
Every leg is compofed of four joints, and ter- 
minated bya fingle claw. The firft joint is 
affixed to the breaft; the next to this is fome- 
what crooked, as is likewife the third, which 
confifts of a matter fomewhat more bony and 
horny than the others, and is armed with pro- 
minent brown red little points like teeth, and 
furrounded laterally with numerous hairs. The 
fourth joint is very fmall, and is armed with a 
{mall claw. The mufcles likewife, and their 
infertions may be feen very diftinly here, by 
the help of which the bony joints are beauti- 
fully moved. 
To the fecond divifion of the thorax, which 
is the third ring of the body, and properly con- 
ftitutes the loins, and is covered both above and 
below with a fhield of a horny little bone, is 
annexed a fecond pair of legs, Tab. XIII. fig. 
tv. d, which confifts of five joints and one claw; 
and are here and there furnifhed alfo with hairs. 
Somewhat behind thefe, the follicles or little 
fheaths e, wherein the firft pair of wings are 
concealed, are feen oneach fide. ‘Thefe fheaths 
are here and there interwoven with air veffels, 
which appear on their external furface, like 
common little veins or nerves. When the 
Worm is juft going to caft its skin, the internal 
or Under wings are folded in a wonderful and 
elegant manner, and appear through their ex- 
ternal coats or follicles. 
There apperrs on the third ring of the tho- 
rax, which is the fourth of the body, the in- 
fertion of a fecond pair of wings, which are 
much lefs than the firft pair, and are wholly 
covered by them. This firft pair likewife partly 
covers the hindermoft or laft pair of legs, which 
confift like the others of five joints and one 
claw; and are adorned with numerous hairs. 
The firft ring of the abdomen, or the fifth 
annular incifion of the body, is all even and 
{mooth, nor is it joined to the legs; the wings; 
or any other part. To the fix following rings 
_are affixed very beautiful branchiz or gills ff; 
perpetually fluttering, and beating up and down 
with a tremulous motion. By the help of thefe 
Clutius erroneoufly thinks the Worm fwims ; 
but thefe partsare undoubtedly the branchiz or 
gills of the creature: In Lobfters, Crabs, and 
Cuttle-fth, which approach in many refpects 
to the ftructure of infects, we conftantly find 
thefe little parts framed and fituated in the 
fame manner, with this difference only, that in 
Crabs and Lobfters they are enclofed in a hard 
fhield, wherewith the back is covered, but in 
thefe as well as in the Cuttle-fith, they are fitu- 
ated higher on the body than in the Ephemeras. 
In the figure of this Worm given by Crachtius, 
twelve gills are exprefféd on each fide. This 
etror feems to have arifen from a wrong view, 
fince there are only fix on each fide, the whole 
only make twelve. _ . : 
The eighth and ninth divifions of the belly, 
which conftitute the twelfth and thirteenth rings 
of the body, are all even and fmooth. Thefe 
are fucceeded by the tenth or laft, that is, the 
fourteenth divifion of the body. ‘This is adorned 
with threé hairy and briftly tails, Tab. XIII. 
fig. 1v. g, to which are alfo added two crooked 
appendages, which are not fo remarkable in the 
females ; but in the males they are likewife 
accompanied with fome other little appendages 
underneath. 
As to the colour of thefe Worms, the {mall- 
eft appear of a pale blue with a tinge of green. 
This, however, cannot be properly faid to be- 
long to the creature itfelf, but is rather owing 
to the vifcera which are feen through. The 
eyes of all thefe Worms are of a blackith brown 
colour, and the back is fpeckled with pale 
brown fpots, which increafe by degrees with its 
age. The mouth is palifh, and is furnithed 
with redifh brownteeth; of this colourare alfo 
the 
