Was looking on the weekend to put breather hoses on my tranny (already have my diffs done) but came across a problem. Was hoping someone could save me the time of investigating any further!

The tranny box has two breathers at each of the gear levers, and one just down to the left, mb 3 inches. Whats the 3rd one for??
Also, how do you unscrew the breathers, cos on the diffs, the breathers had a hex shaped bottom where you could put a spanner to it. All these 3 dont have anything, actually cant even tell if they are screwed in to the tranny, or what!
Any help would be appreciated.
Cheers