Reference for NA butterfly checklist

Wed Mar 24 09:52:59 EST 1999

Hi,
   Could somebody tell me the most recent published checklist of North
American butterflies (I need a reference)? Somebody mentioned this on the
list a short while ago, but I have already deleted the message.

Thanks!

Niklas

_________________________________________________________________________

   Niklas Wahlberg                          
   Department of Ecology and Systematics    
   Division of Population Biology           
   PO Box 17 (Arkadiankatu 7)               
   00014 University of Helsinki
   Finland                                                         
   p. +358-9-191 7378, fax +358-9-191 7301  
 Check out our www-site:                    
  http://www.helsinki.fi/science/metapop/   