Whilst examining the tract of Lower Palæozoic rocks and metamorphic schists around Killary Harbour, in Connemara (an examination primarily undertaken to ascertain the relations of the fossiliferous sediments to the schists in that area), an extensive tract of Arenig rocks has been discovered on both sides of the harbour. In 1905 Didgmograpti of the extensus and superstes types were found, and during last Summer several specimens, of Phyllograptus and Tetragraptus also, together with many other forms.