The first part of this paper contained a review of the existing nomenclature of trappean-rocks, and the following arrangement was given as that which the author had found to be most useful for practice in the field:—1st, Ash and volcanic conglomerate. 2d, Interbedded augitic traps (greenstones and basalts). 3d, Interbedded felspathic traps (felstones, porphyries). 4th, Intrusive augitic traps. 5th, Intrusive felspathic traps. By adopting a different colour for each of these classes, the general relations of an intricate trappean district could be shown at a glance.