42 THE BRITISH WOODLICE.
When we examine the abdomen, we find that the appendages
are plate-like, with the exception of the last pair (fig. 13), and;
they all agree in having two divisions, an arrangement which
would prove awkward in limbs used for walking or feeling.
The inner plate (or endopodite) is in structure a gill, but
the blood that passes through it, is enabled to take up oxygen