Missing level?

The game was supposedly supposed to have 32 major levels originally but by the time the game was released it had only 15. I'm guessing most of them never left the planning stages, but during the end credits when its panning over the various levels (in order of level number) between the cave level and the lava level it shows a level that with a giant worm like bug walking around on a cage floor type dungeon area.

Since the same exact bug is in the GameCube Mario game (recycled into it when the enemy was cut in Mario 64 I guess) is the level there or not? Like is it a secret level that I missed, or is it just left over in the data of the game but unplayable?

Btw a pic of the bug in super mario sunshine is here http://img.gamespot.com/gamespot/images/2002/gamecube/mariosunshine/msun_0723_thumb002.jpg

EDIT: Oops, its part of the tiny huge island level, Its there, I had just never been to that part.