40 
GLIMMERCHAFFER. 
finely webbed with minute hairs, and most curi- 
ously formed for exercising the office of fins or 
oars. The larva is of a highly singular aspect, 
having a very lengthened body, furnished, exclu- 
sive of six legs on the fore-parts, with a great 
many lateral appendages or processes down the 
botly ; those towards the extremity considerably 
exceeding the rest. In its motions it is extremely 
agile, swimming in a kind of serpentine manner, 
and preying on the smaller and weaker water- 
insects, minute worms, &c. the head is armed with 
a pair of forceps, pierced on each side the tip with 
a small foramen, through which it sucks the juices 
of the animals on which it preys: the colour of tliis 
larva is a very pale or whitish brown, with a high 
degree of transparency, which renders it a higldy 
curious object for the microscope : its length, 
when full-grown, is about three quarters of an 
inch. When the time of its changes arrives, it 
forms for itself a small oval cell or case on a leaf 
of sedge or other convenient water-plant, and after 
casting its skin, becomes a chrysalis: this change 
usually takes place in the month of August, and 
the complete insect emerges in that of September. 
When these animals are congregated together 
in great multitudes on the surface of the water, 
which frequently happens in hot weather, they 
have been observed to difluse a strong or disagree- 
able smell to a considerable distance. Like other 
water-beetles, they ffiy only by night. They de- 
posit their eggs, which are very small, white, and 
of a somewhat cylindric form, on the stems of 
