Here then are the icons associated with the members of the Legion of Super-Heroes.
And as an example of how they are used, here is the Wheel of Terror from Legion of Super-Heroes (v3) #1 by Keith Giffen. You will see each of the Legionnaires shown on the outer circle.
On the inner circle are four more that we can easily recognize as representing Bouncing Boy, Supergirl, Duo Damsel, and Light Lass.
Here is an enlargement of the cover of Legion of Super-Heroes (v3) #12 with each of the then-current 22 Legionnaires' icons. Art is by Steve Lightle, but I don't know if he also drew these, or if they were used from the Master List above.
After the last five members of the Bronze Age joined in LSH (v3) #15, we saw their icons being used during LSH (v3) #51 "The Trial of Brainiac 5." In that issue the mission monitor board itself was shown as the "tally-board" for the Legionnaires to vote either "Guility" or "Innocent" on whether what Brainiac 5 had done to The Infinite Man was murder or not.
The most interesting thing here is that Tellus' icon is a simplified version of what is listed on the Master List. This evidently represents the gem on his forehead.