Hi Kiel,
This is an error in the BOM. The crystal is a 250MHz Vectron crystal. It will need some work on the board to get the crystal to drive the ADC. Moreover, the crystal performance is very lackluster. You can see below how bad the SNR degrades with the VCC6. At the time of the release of the AD9467-FMC-250EBZ, the VCC6 was the only 250MHz crystal oscillator with any decent performance. Since then, there have been others, most notably Crystek. You can see from the curve below how the SNR keeps up with the Rohde&Schwarz SMA100A.
We are in the process of redesigning this board to include the Crystek CCSO-914X series crystal oscillator.
Regards,
Umesh