Does anyone know why the price for a Mutual Fund in a 401k account would be less than the price when not in a 401k account?

ex. Janus Balanced Fund in a 401k account is $21.15 but the market quote is $27.30 as of 18 Oct 12.
Another one is Janus Forty Fund in a 401k is 14.36 but market quote is $38.27, that's a huge difference.

Been trying to figure out why the big difference in quotes.
Your help is greatly appreciated.