TRACHEA TA 



407 



The chelicerae are very strong, and project in front of the 

 head ; the lower limb is moveable, and works vertically against 

 the fixed upper half. The pedipalpi are limb -like. The 

 anterior pair of legs belong to the head; their basal joint 

 serves as a cutting (maxillary) process, at the side of the 

 mouth, an arrangement similar to that found in Zimulus 

 and Scorpio. Like the pedipalpi, they are directed forward, 

 and like them may serve as tactile organs. 



The three posterior legs, which are borne by the three 

 free thoracic segments, are clawed. Another point in which 

 these Arachnids resemble Insects is the presence of a well- 

 formed tarsus. The abdomen is composed of nine or ten 

 segments. 



The basal joint of the fourth paif of legs bears five curious 



Fig. 234. — Under side of Galeodes arane- 

 oides, with legs and palpi truncated. 



a. Coxa. 



e. Basal leg-joints. 



e". 1st joint of 1st pair of legs. 



/. Labium. 



h. Backet-sliaped appendages. 



i. External toifice of genital organs. 



k. Tongue. 



m. Pedipalpi. 



0. Openings of respiratory organs at base 

 of 2nd pair of legs. 



p. Orifices leading to tracheae at fore margin 

 of 2nd and 3rd segments of abdomen. 



r. Anus. 



t. Fixed upper fangs or claws of chelicerae. 



•«.. Moveable lower fangs or claws of cheli- 

 cerae. 



racket -shaped processes, pointing backwards, of unknown 

 function. 



The tracheae open to the surface by three pairs of 

 stigmata ; the anterior pair are on the thorax, the other two 

 open behind the second and third abdominal segments. 



The stomach is provided with lateral caeca; the anus is 

 posterior, and the genital orifice opens on the first segment of 

 the abdomen. Paired coxal glands are found in the thorax ; 

 they are much coiled, but apparently have no opening to the 

 exterior. 



