NATURAL HISTORY. 81 
water: they are, however, most abundant in 
July and August. I have collected great num- 
bers of them on a warm day, in the latter 
month, in a small cloth-net, immersing it about 
an inch below the surface. They are mostly 
colourless, in ponds covered with herbage, but 
in small collections of rain water, on a loamy 
soil, they are of a fine rich colour; they are 
never very numerous in waters frequented by 
the common water-flea (Daphnia pulex), though 
frequently met with in neighbouring pools. 
In plate 9, figure 1, is a drawing of this 
Cyclops of its real size, and figure 2 of the same 
plate is a magnified representation of it. 
The body of this creature is covered with 
erustaceous or shelly plates, which overlap each 
other, and admit both of a lateral and vertical 
motion between them. Their ends do not meet 
on the under side, but have sufficient space 
between them for the insertion and play of the 
organs of respiration (a). The rostrum, or 
beak, is short and pointed; it is a prolongation 
of the first segment or convex plate, which, 
terminating obtusely, forms the head. A little 
above the beak is embedded beneath the shell 
a compound eye of a dark crimson colour, nearly 
ES 
