What was this instrument?

I am going to do my best to describe an instrument that my elementary school music teacher Ms. Lula used to pass around to the class. She would bring in a number of cases and when you opened them laying neatly and perfectly fitted were this little instruments that were sort of like a marimba bar but hollow but the thing is each one had a hinge on it with a rod and at the end of the rod was a mallet. So when you swung the bar it actually swung the mallet also and then struck the bar sounding whatever note was engraved on the side of the little instrument. There were a bunch all with different notes and she would hand them around and we would play chords and also melodies with them. Probably one of the coolest music exercises. Now I am a lover of music who teaches guitar lessons. So that's the best description I think I can come up with. They were handheld little note makers. I remember them being kind of big but I was small so they probably weren't that big. Anyway if anyone out there in the world can tell me the names of these instruments I would be thrilled because I've scoured Google with no success. Thanks!