There are three forms of membership in the society.
The first and most typical is regular membership. Regular membership in the society costs $2.00 per year, which is paid during the meeting registration period (even if you are not attending).
The next type is patron membership which is held by members who have made at least a $100 donation. A list of patron members can be found here.
The final membership is honorary membership, which is bestowed upon people who have been nominated by the membership. A list of the honorary members can be found here.