Search for Unstable Heavy and Excited Leptons at LEP2                          
  
Searches for unstable neutral and charged                                      
heavy leptons, N and L, and                                                    
for excited states of neutral and charged leptons,                             
nu*, e*, mu*, and tau*,                                                        
have been performed in e+e- collisions using                                   
data collected by the OPAL detector at LEP.                                    
The data analysed correspond to an integrated luminosity of about              
58 inverse pico-barns at a centre-of-mass energy of 183 GeV, and               
about 10 inverse pico-barns each at 161 GeV and 172 GeV.                       
No evidence for new particles was found.                                       
Lower limits on the masses of unstable heavy and excited leptons               
are derived.                                                                   
From the analysis of charged-current, neutral-current, and photonic decays     
of singly produced excited leptons,                                            
upper limits are determined for                                                
the ratio of the coupling to the compositeness scale,                          
f/Lambda,  for masses up to                                                    
the kinematic limit.  For excited leptons, the limits are established          
independently of the relative values                                           
of the coupling constants f and f'.                                            
  
 Parallel session :11                  
 Plenary  session :7a