Continuous Line charts are not showing all Series Data

We have a Continuous Line chart built from ~350 elements in the "series." We're only seeing about 23 of these in the series list and we're not positive that we're seeing all of the series lines. It's critically important that the user is able to scroll through the list of all of the series data so that they can identify items that are either exceeding thresholds or vastly under the threshold.