INTRODUCTION 



IX 



On the front of the head are the eyes, usually eight in 

 number, differing in size and arrangement according to the 



TARSUS 



claw or 



' MANDIBLE 

 •MANDIBLE 



•MAXILLA 

 UM 



o 

 m 



i 

 > 



x 

 o 



> 

 X 



OPENING 

 OrAIR SACS 



EPIGYNUM 



MANDIBLES 



CLAW 



\&&t 



TRACHEA 

 >INNERETS 



> 



o 

 O 



m 



Fig. i. Diagram of the under side of a spider, with the legs removed except one. 

 Fig. 2. Front of head, showing the eyes and mandibles. 



kind of spider. The sight of spiders is distinct for only short 

 distances. Spiders of middle size can see each other, and the 



