The Larkin DNA project continues a sampling effort to link Y-STR haplotypes with specific ancestral geography to serve as a guide for genealogical research. The Type 12 group previously identified has been expanded and confirmed in County Wexford. Two new Types have been identified in Ulster which are part of the L21 clade of the R1b haplogroup. Type 15 has the distinctive DYS425 deletion associated with Clan Colla. Type 16 is diverse but lies within the L21 clade and probably represents the Ulaid tribes native to Ulster prior to 400 CE. Samples characteristic of Larkin Type 01 previously identified in the Shannon River valley were also found in Ulster supporting a shared Ui Niall ancestry between Ulster and the Irish midlands.