The system was unable to mount the filesystem that was specified because the super-block indicates that the filesystem might be corrupted. This is not an impediment for read-only mounts.
If you don't need to write on this filesystem, mount(1M) it using the -o ro option. Otherwise, do as one of the message continuation lines suggests and run fsck(1M) to correct the filesystem state and update the super-block.
For more information on using fsck(1M), see the section on checking filesystem integrity in the System Administration Guide, Volume I.