NO you cant wink wink hint hint.....
You have to sue him in small claims court for the 1/3 since you have a lease and he signed it and is legally responsible for it.
BUT you MUST pay the landlord the FULL amount or you will be evicted.
So start looking for a new roomate, give the old one 10 days to paick up the stuff or you will toss it, keeping a few things to yourself..hint hint...