ARTIIROPODA 



181 



segments. The abdomen possesses nine or ten segments. 

 There are three pairs of appendages attached to the head and 

 three to the thorax. The respiratory organs consist of tracheae 

 which open by means of three pairs of stigmata, one pair on 

 the ventral side of the third thoracic segment, the other two on 

 the second and third abdominal segments. Only two genera 

 are known in this order (Fig. 175). 



Order 5. Phalangida 



The Phalangida (Gr. (fraXdyyiov, spider) are commonly called 

 harvest men or daddy-long-legs (Fig. 176), and have an unseg- 



Fir.. 176. Oligolophus spinosus, a harvest man or daddy-long-legs; adult male, enlarged 

 about two diameters, i, chelicerse; 2, pedipalpi ; 3, 4, 5, 6, legs. (After Shipley and 

 MaeBride.) 



mented cephalothorax, a swollen abdomen of six segments, and 

 four very long legs. They are harmless little animals, avoiding 



