

120 



PRACTICAL ZOOLOGY 



but agree in several important respects: (i) they have no an- 

 tennae; (2) there are no true jaws; (3) the first pair of append- 

 ages are nippers, termed cheliceras; and (4) the body can usu- 



Fig. 66. — The king or horseshoe crab : A, dorsal view ; B, ventral view. (From 

 Shipley and MacBride.) 



ally be divided into an anterior part, the cephalothorax, and a 

 posterior part, the abdomen. 



Of the twelve orders of Arachnida only four need be mentioned, 

 since they contain most of the living species. 



Order 1. Araneida. — Spiders. 



Order 2. Scorpionidea. — Scorpions. 



Order 3. Phalangidea. — Harvestmen, or Daddy Long- 

 legs. 



Order 4. Acarina. — Mites and Ticks. 



REFERENCES 



The Spider Book, by J. H. Comstock. — Doubleday Page and Co., N. Y. 



City. 

 Common Spiders, by J. H. Emerton. — Ginn and Co., Boston. 



