OK, UCSC's student orgs site is really jacked up and it's no wonder the OP doesn't know what she's doing. They don't differentiate at all between the types of sororities and often whether or not the group is a fraternity or a sorority. Plus the "fraternities and sororities" page doesn't actually list them.
http://www.metroactive.com/papers/cr...rats-0239.html
Mass LOL at the "international multicultural fraternity Theta Chi."