310 DIPTERA. 
covered with a rough granulated skin of 
various colours ; and is divided into 
twelve rings, of which nine are perfo- 
rated by spiracuLe, having one on each 
side ; do you remember Avhat they are r 
Lucy, Yes, I do. They are little 
breathing holes, and are generally marked 
by a coloured ring close round them. 
Mother, Very well. This larva is 
very slow in its motions, and never moves 
horizontally through the water as fishes 
do. When at rest it expands its circular 
tail of filaments upon the surface of the 
water^ like a fan, from which the body, 
that always hangs downwards, seems to 
be suspended. 
Lucy, Do these curious creatures in- 
habit our ponds ? 
Mother, I believe they may be very 
commonly found there; but we seldom 
think of seeking for those wonders, which 
are a little out of our beaten path. I had 
once the pleasure of finding one of these 
larvae in my water glass, after dinner, 
where I could readily observe its motions ; 
