ARTHROPODA 





body is greatly flattened dorsoventrally. They are strikingly 

 like the true scorpions in many respects, but there is no narrow 

 postabdomen and no poison spine. The cephalothorax is much 



the same as in scorpions. The abdomen is oval and conn 

 of eleven segments. Near the genital 

 opening on the second abdominal seg- 

 ment are spinning glands, which secrete 

 fine, silky threads to attach the eggs to 

 the abdominal wall ; these resemble 

 the spinning glands found in spiders. 

 There are only two pairs of stigmata, 

 on the first and second abdominal seg- 

 ments, and these connect, not with lung- 

 books, but with tracheae. 



Order 3. Pedipalpi 



FlG. 173. Chi ivaisii, a 



book scorpion. 2-6, second to 

 sixth pairs of appends 



m Lang's Comparative 

 Anatomy.) 



The Pedipalpi (Lat. pes, foot, and 

 palpus, feeler) are commonly called the 

 scorpion spiders (Fig^ 174). They are tropical animals 

 attain a considerable size. Of the six pairs of appendages 

 on the unsegmented cephalothorax, the first pair is small and 

 said to be poisonous, the third 

 pair is extremely long and slen- 

 der. The abdomen is flattened 

 and consists of eleven or twelve 



174. Phrynus, a scorpion spider. (From Cuvier's Animal Kingdo 



ments. It is round in outline in some species, in others the 

 three posterior segments are very narrow, recalling the post- 

 abdomen of the scorpions, and the last segment is provided with 

 a long lash or filament ; hence these are often called the whip 



