418 THE INSECT WORLD. 
still enveloped in a very thin skin, of which a last moult, after 

Fig. 390.—Larva of an Ephemera. 
a few hours, frees it. This 

j 
/ ‘ 
f \ : 
2 
Fig. 392.—Cloé€on diptera. 
are insects of a well-defined 
Fig. 391.—Pupa of an Ephemera. 
skin remains sticking to the plant 
on which the moulting was effected, 
preserving the shape of the insect. 
This moult is peculiar to the Ephem- 
ere; it is the transition from the 
false imago (pseudo-imago) to the 
Imago. 
In the same family is the genus 
Cloéon, whose larvee prey on minute 
insects. The Cloéon diptera (Fig. 
392), which has only two wings, is 
often to be met with in houses, 
resting on the window panes and 
curtains. All these insects keep 
badly in collections ; they lose their 
shape, and their members are so 
fragile that the least shock suffices 
to break them. 
The Libellulas, or Dragon-Flies, 
type. The elegance of their shape, 
