This may want to just get folded into 24857, but filing separately to start. In the volumes interface defined by 24857, we haven't explicitly defined how many volumes to show or how to paginate them, so if you have volumes in excess of your RESTdefaultPageSize syspref those volumes cannot be seen. We should make it show them all. Or paginate, but showing them all would be more consistent with other bits of the catalog.
Fixed in the parent bug patch set, as it has not yet been pushed to master.