The late Mr H. T. M. Witham read in 1830 to this Society, and published three years afterwards in greater extension, an inquiry of much interest respecting two fossil trees found in Craigleith Quarry, a mile and a half from the north-west outskirts of Edinburgh. The general points of this inquiry are, that trees of very great size lie, completely fossilised, in the very compact sandstone of the quarry, at a great depth below the rock surface, slightly inclined to the-dip of the strata, with their structure so finely preserved in the fossilising material as to be beautifully shown before the microscope, and recognised as that of the Pinaceous Family, and of the section to which belongs the existing Araucaria. These trees have been generally known to fossile botanists by the name of Araucarioxylon Withami. An opportunity having occurred this year of confirming and extending the inquiries of Witham, it has been thought right to take advantage of it, again through the medium of the Royal Society.