If you wish to pay by check, you may do so.  Your membership will not become active until your check has been received and processed.

After filling out the member information, at this screen, select Invoice Me

That will take you to your Profile. 

Click View/Pay Invoice

You will then see your invoice. 

Make your check payable to Society for Scientific Exploration and mail it to the address shown on the invoice. 

Be sure to include your invoice number on the check.

Allow up to 10 business days for processing before your membership becomes active.