AP 



TH 



ABD 



FIG. 1 62 A. Dorsal view of a wood-luuse (Omscus), a typical Isopod, 

 but of terrestrial habits after Webb and Sillem. The abdominal 

 appendages or pleopods are penetrated by minute air- containing 

 fcubes which form a respiratory system adapted for terrestrial con- 

 ditions. In the marine Isopods, the endopodites of the abdominal 

 appendages are gill-like and serve for aquatic respiration. The 

 number of segments and appendages is like that in the crayfish. 



A., Antenna. 



TH., A segment of the thorax. 

 A. P., Last pair of abdominal appendages. 



H., Head. 

 ABD., A segment of the abdomen. 



