what screws into bottom of 5spd tranny?

[sixleggedinsect]

had the car up on a lift today and got to have a look around. things look very different when your nose is not pressed up against the underside of the car.

i noticed two empty threaded holes on the bottom of the transmission. they looked clean, which worried me, as if something had recently been screwed into them and come out. the holes were about six inches apart, and about 1/4" in diameter, maybe something like a M5 or M6 thread?

does anyone know what those two holes are supposed to be filled with?

anthony