PieterP:
Page 2 of the datasheet shows the pinout. One pin is not connected, and another one is the case ground.
Then read this: I'm breadboarding an Arduino. How do I connect a 4-pin crystal oscillator? - General Electronics - Arduino Forum
And this: Compiling Optiboot - ATmega328P at custom frequencyPieter
thank you for the links maybe i was premature in posting as i picked up the crystal on my lunch break and have not been able to research it yet.