A Short Explanation of the TABLES. 
FIG. VI. 
The Nympb-Vermicle of a fingular kind of a 
Dragon-fly. 
a Thehorns. 40 Six long legs. 
c The little bags, or cafes of the wings. 
d The hairy belly. . 
e The triangular appendages of the belly. 
Bd Gi Vi. 
The Nymph-Vermicle of the fimalle Dragon-fy, 
found common in Holland. 
ACB. XT, 
Pea,” 1 
The Worm of the Ephemerus, of the firft year's 
growth, three quarters of a Dutch inch long, 
in which 1s not the leaf? appearance of wings ; 
but the five gills are vifible on the back, from 
whence come in fight the ten lower rowing 
fits. 
BokiGue ik 
The Worm of the Ephemerus of the fecond year’s 
growth, five thirds of an inch long ; the little 
bags or cafes in which the wings are enclofed. 
P°r'G. “iil. 
The Worm of the Exphemerus of the third year’s 
growth, a female, about two inches and a half 
long ; provided with the little bags or cafes of 
the wings, which are now vwifible. 
FIG. Iv. 
The largeft Worm of the Ephemerus, in which all 
the parts elegantly and diftinétly appear, 
a The eyes, which are twice as large as thofe 
of the female worm." 
£6 The horns, and the diftine articulations 
of them. 
¢ The forceps, mouth, or dentated jaws, by 
which they dig into the earth. 
dd The firft, fecond, and third pair of legs, 
with their articulations or joints. 
e The little bags or cafes of the wings, which 
enclofe the firft pair of wings, like a tender 
little flower, {hut up in its cup. 
Sf The gills, perpetually fluttering, very white © 
and limpid, and covered with innumerable 
fine hairs. 
g Three briftly hairy tails, with their appen- 
dagee. 
The rowing fins in Fig. I. and JII. may alfo 
be feen. 
i eee 
Oblong or hollow tubes, or cells, made in the mud 
or clay, in which the Worm of the Epbemerus 
creeps, and is moved and nouri(hed. 
aa The tubes made in the mud by the largeft 
worm, 
bb The tubes that are hollowed out by the 
{malleft worms. 
FIG. VL 
The male Ephemerus freed from the Jif exuvia; 
or fein, entirely fiript of its former likenefs of 
a Worm: 
| FIG. VIL. 
The Worm of the female Ephemerus, about to under- 
go in alittle time its change, in which may be 
feen the wings through their little bags or cafes. 
aa The little fheaths, cafes, or bags of the 
wings, through whofe {mooth external little 
membranes may be feen diftinctly, the folded 
wings lying hid within them. 
FIG. VII. 
A female Ephemerus, fiript, on the furface of the 
water, of its fein; and quitting the form of a 
Swimming Worm is changed into a flying infec. 
fr Cale 
The ‘manner how the wings expand themfelves, 
But in the following X1Vth Tab. Fig. 1. un- 
der let. ®*® may be feen the natural Soldings 
of the wings, which here feparate by degrees 
one from another. 
: ee Os Beal. @ 
The fame wing, fir fmoothing its Jerpentine 
Soldings, afterwards its oblong folds 
F I G. XI: : 
The fame wing not entirely expanded, 
FIG. XU. 
The male Ephemerus, employed in changing its 
fein, which is very flowly completed on dry 
land. Here half the body is now fiript of its Skin. 
The fein is ftript of the bead, thorax, and 
legs, in the Jame manner as we draw our feet 
out of our shoes; but as to the wings, the fein 
is drawn off them in fuch a manner, that the 
infide 1s turned outward. 
Por Ge Xm, 
A male Epbemerus, which bas almoft gone through 
tbe change of its fein, fo that its double external 
wings aud tail might be taken only for a flender 
part as yet to be caft off: 
BP d..G..\ XIV. 
The very flender caft Jeins of the Ephemerus, which 
do not retain the form, as here reprefented, 
becaufe the parts in which the wings were in- 
cluded, are commonly wrinkled, and by that 
means change the form. 
FIG. XV. 
