A SOW BUG 



37 



as in the decapods, are attached to the abdominal legs. With a 

 fine needle separate the flattened appendages of the first five 

 abdominal segments. The endopodite serves as the gill, while the 

 exopodite is large and platelike and covers the endopodite. 



Observe the appendages of the head. But one pair of antennse 

 will be seen, the second, the first pair being rudimentary in sow 

 bugs; this feature is apparently an adaptation to a terrestrial life. 

 The other mouth parts consist of one pair of mandibles, two pairs 

 of very dehcate maxillae, and a pair of maxillipeds which are 

 platelike and cover the other mouth parts. The maxillipeds 

 belong to the first thoracic somite, which is fused with the five 

 cephalic to form the head. 



Exercise, Draw a dorsal view of the animal on a scale of lo. 

 Number the thoracic and the abdominal segments. 



