It happened weeks ago but I just saw it.
They go to Area 51 to examine bones that look alien. Dean Haglund is a guest in the episode who played Langley from the Lone Gunmen:
Hulu - Bones: The X in the File - Watch the full episode now. (http://www.hulu.com/embed/sM9jbo-xJ7fRdvu13fmHwA)
Yeah - I remember this episode. Chock full of area 51 conspiracy "people"