26o AN NU LATA. ' 



and sucking. The best known are skin-parasites (or ecto- 

 parasites) upon various animals. The type shown is a 

 mange-mite which tunnels in the skin of the domestic 

 animals, and gives rise to the painful " itch " or skin mange. 



Other Arachnida are the httle long-legged " harvest- 

 men," the book-scorpions and certain parasites. Lastly, 

 there is an interesting animal, the king-crab {Limulus), 

 which lives in mud of shallow seas in the Oriental region. 

 It breathes by gill books and has a large cephalothoracic 

 shield, six pairs of chelate appendages and a long post- 

 anal spine. It appears to be an aquatic Arachnid of very 

 primitive character. 



Fig. 183. — The Harvestman 

 {Phala?igiu77i cormitimi). Magnified. 



[Table. 



