Pearlstons. 271 Geographic Situation. It is found in the neighbourhood of Tokay in Iiun- £ ar y, near Ochotfk in Kamfchatlka, and near Sandy ^ r ae in the north of Ireland. Some of its tranfirions t° other foffils occur in the interefting Ifland of Egg, ° n e of the Hebrides, and near Sandy Brae in Ireland. ^°es the pearlftone of Sandy Brae belong to the ^ 0e tz trap formation ? Obfervation. ' . *1 he veficular variety, particularly the longifh, often ears a ftriking refemblance to pumice j indeed it ap pears to pafs into it. SIXTH