26 SYNOPTIC KEY 



3(6) Abdomen with a tail-like projection, or segmental 

 caudal filament 4 



4(5) Tail stout and armed with a sting at the end; first 

 pair of legs not greatly elongated; a pair of comblike 

 appendages on the lower side of the second abdominal 

 segment in the adult. (Pratt, 404; Comstock, 21.) 



Order Scorpionida 



5(4) Tail slender, whiplash-like, without sting; first pair 

 of legs much longer than the others; without comblike 

 appendages on the abdomen. (Pratt, 406; Com- 

 stock, 16.) 



(Family Thelyphonidae.) Order Pedipalpi 



6(3) Abdomen without a tail-like projection. 7 



7(8) Pedipalpi with pincher-like claws. (Pratt, 408; 

 Comstock, 39.) Order Pseudoscorpionida 



8(7) Pedipalpi without pincher-like claws. 9 



9(10) Abdomen joined to the thorax by a slender stalk; 

 front legs greatly elongated and with whiplash-like 

 tarsi. (Pratt, 407; Comstock, 16.) 



(Family TarantuHdae.) Order Pedipalpi 



10(9) Abdomen broadly joined to the thorax. 11 



11(12) Legs usually very long and slender, thorax indistinctly 

 divided into three segments. (Pratt, 410; Comstock, 

 53.) Order Phalangida 



12(11) Legs moderately long; head distinct from thorax; 

 thorax distinctly divided into three segments. (Pratt, 

 408; Comstock, 32.) Solpugida 



13(2) Animals wormlike; internal parasites in vertebrates. 

 (Pratt, 455.) Order Linguatulida 



14(1) Abdomen not segmented. 15 



