Republican presidential candidate Rick Perry admitted Sunday that he didn't know the names of all of the Supreme Court justices, who he calls "judges."

In an interview with the Des Moines Register Friday, Perry struggled for six seconds to remember the name of Justice Sonia Sotomayor. He called her "Montemayor," and was eventually reminded of the correct name by one of the newspaper's staffers.

Perry also claimed that there were eight justices on the court instead of nine.

"Well, obviously I know there are nine Supreme Court justices," Perry told Fox News host Chris Wallace Sunday. "The fact is I can't tell you -- I don't have memorized all of the Supreme Court judges."

"[Americans are] not looking for a robot that can spit out the name of every Supreme Court justice or someone that's going to be perfect in every way," he added.

At a CNBC debate in early November, Perry also forgot which three federal agencies he would eliminate as president.

Watch this video from Fox's Fox News Sunday, broadcast Dec. 11, 2011.