Haven't you reasoned it out yet, Legionnaires? We are the delegates from Corvan IV! 
Superboy and the Legion of Super-Heroes #246 is an issue of the series Superboy and the Legion of Super-Heroes (Volume 1) with a cover date of December, 1978.
Synopsis for "Will the Last One to Leave Mercury Please Close the Planet?"
The Legion must solve the mystery of vanishing people on Mercury.
Appearing in "Will the Last One to Leave Mercury Please Close the Planet?"
Featured Characters:
Supporting Characters:
Antagonists:
- Thermoids (heat beings of agitated molecules)
Other Characters:
- Science Police
- Dr. Zebx
Locations:
- Mercury
- Medivac-Lab
Items:
Vehicles:
Synopsis for "A World for the Winning!"
Three Legionnaires discover that the Fatal Five have used their science in order to advance the status of living on the planet Corvan IV. Now that they are delegates of the plant, they want to apply for United Planets membership. When their application is rejected, the Five become angered and take down Colossal Boy and Element Lad, leaving Superboy to scurry off and get more help.
To be continued...
Appearing in "A World for the Winning!"
Featured Characters:
Supporting Characters:
Antagonists:
Other Characters:
- President Boltax
- Corvanians (alien race) (First appearance)
Locations:
- Corvan IV (First appearance)
- Metropolis Spaceport (30th Century)
Items:
Vehicles:
See Also