Class Insecta :
- Body is divided into three parts : head, tho-rax and abdomen.
- Wings are found.
- Appendages on head are antennae, mandi-bles and maxiliae.
- The walking legs are three pairs.
Class Arachnida : - Body is divided into two parts: cephalotho¬rax and abdomen.
- Wings are lacking.
- Apendages on head are a pair of chelicerae and a pair of pedipalps.
- The walking legs are four pairs.