The variety of saponite described in the following note was first obtained by Mr. Waiter Burns, of the Geological Society of Glasgow, from a quarry in the Cathkin Hills, about three miles S.S.E. of Glasgow, The quarry is hewn out of dark-coloured dolerite, rich in olivine, which restg on beds of felspathic ash. The dolerite has in places been converted into a green-coloured fibrous variety of saponite (Boulingite), which is found in veins of from 2 to 8 inches in thickness. This variety has been analysed by Prof. Heddle, as well as by Mr. G. Wallace Young and Mr. G. B. Hannay.