It sounds like Small Continents to me.
I am sure I have played Continents maps with three large land masses, but I am not sure about four.
The continents on Small Continents can be large enough to spawn a couple civs. Maybe even three some times?
The mouse-over for the plus map just says something like “additional scripting for CS placement”. In my experience, that means the CS are further way, and tend to be in clusters. I like it, as (1) it removes the temptation to worker steal; and (2) early CS kills by an AI become rare. But there is a real draw back in that many fewer early CS quests are available.