listed in Pender's 'Census' of 1659

Breen: 26
Brian: 48
Briane: 6
Brine: 18
Bryan: 258
Bryane: 78
Bryen: 298
Bryne: 52
Bryon: 60
O Breene: 38
O brien: 72
O bryan: 130
O Bryn: 22
O'Brine: 58
O'Bryen: 424
O'Bryon: 30

From the numbers of Irish, Scotch and English listed in Pender's 'Census' of 1659.

Locations of the variant spelling O bryan in Pender's 'Census' of 1659