Jacks mention of a picture in Southern Scotland showing one of these instruments in the 19th.C.reminded me that Neil Munro describes the instrument in one of his books and calls it a "Dollan," this being well prior to the name bodhran being used for the instrument, if the information in one of the above posts be correct.            

Munro was a gaelic speaker although he wrote in English, perhaps someone who is a gaelic scholar [I use the term in its Scottish context] can check if "Dollan" be from the gaelic.