The igneous succession in Mount Royal is outlined emphasizing the fact that there were two distinct advances of a nepheline syenite magma.Those rocks which are definitely known to belong to the older nepheline syenite and those known to belong to the younger are described separately.A number of types are described which belong either to the first or to the second intrusion, but whose relations are not definitely known. These include most of the nepheline syenite pegmatites, nordmarkite pegmatites, soda-rich monzonites, syenites and an unusual porphyry intermediate between a shonkinite and an essexite.Seven chemical analyses are given.