Because this guy had hung around lawyers too much. The "T" stands fot "Tier". That's the way they are represented on the GLO plats, eventhough they may refer to then as "townships" in the notes. It was a common term even then. Kinda like Major and Minor contours. No such thing, but that's what some call them.
Plus note that your page is from 1882. This is a resurvey or a retracement. The original GLO's are early 1860ish. Somewhere in between it got corrupted. Many of the Missippi GLO's show Section 22, T 2 East, Range 5 North". And florida was laid out way before Mississippi.
Check the BLM Manual that I recently posted. It refers to the Tiers.