I just answered my own question by going to their web site - here for anyone else is the deal:
Due to the size of our aircraft there are certain limitations to the size and amount of carrying capacity and baggage. Tropic Air permits each passenger one (1) carry on and two (2) checked bags with the following dimensions:
Allowable carry on size accepted are personal bags such as a purse or a small backpack with a maximum weight of 15 lbs. Due to limited cabin space, all carry on must fit in your lap.
Each checked bag has a maximum weight of 33lbs., 62 linear inches with a width limited to 30 inches and height of 15 inches.
Excess and oversized baggage will be evaluated, charges assessed, and will be shipped on a space available basis.