What are the happy and sad face masks that represent theater arts called???

I know they have a name and I am BLANK!!! Please help!!! In case you need to see a picture of what I am asking about visit this site...


The two face masks used on the school logo...


http://www.tjc.edu/Theatre/Index.htmWhat are the happy and sad face masks that represent theater arts called???
Comedy and Tragedy


or


Janus MasksWhat are the happy and sad face masks that represent theater arts called???
Comedy and tradegy
the drama masks or comedy and tragedy