The .vmsn files contain metadata and - in case the snapshot was created with the VM powered on - the VM's memory, which is only important if you want to revert to a snapshot. The important data is what's in each of the .vmdk files. Since manually migrating VM's with snapshots require some additional steps, let me know whether you need the snapshots at all? If you don't need to revert to a previous state, I'd recommend you use the Snapshot Manager and run "Delete All" to get rid of the snapshots prior to copying them to the new destination.
André