THE BRITISH WOODLICE. 5 
When we examine the abdomen, we find that the appendages 
are plate-like, with the exception of the last pair (fig. 13), and 
Dorsal, Plale 
i 
FIG. 9.—THE ‘‘ UPPER LIP,” 
(Oniscns asellus ) 
FIG I10.—THE “LOWER LIP,” 
_ (Oniscus asellus.) 
FIG, II.—A TYPICAL THORACIC SEGMENT 
(Ontscus asellus.) 
they all agree in having two divisions, an arrangement which 
would prove awkward in limbs used for walking or feeling. 
Body Capily x 
(wilh Vibcera 
fs 
Lee MN \ I gp \Bzsad 
FIG, I2,—THE FIFTH THORACIC SEGMENT OF A FEMALE, 
(Oniscus asellus.) 
The inner plate (or endopodite) is in structure a gill, but 
the blood that passes through it, is enabled to take up oxygen 
