In the agglomerate of the volcanic necks of Eastern Fifeshire are incorporated, as has long been known, numerous fragments of sedimentary rock. These, it is generally believed, represent the broken-up remains of the strata which at some former time occupied their sites. Many of them have obviously been subjected to excessively high temperatures, others show no sign whatever of igneous action. Thus, occasionally we find quartzites and lydian stone representing what once must have been sandstones amd clay shale; or, again, the constituent layers of a sandy or carbonaceous shale may be seen to be still adherent and so little altered as to display on a freshly exposed surface admirably preserved plant-remains. Lime-stone blocks also occur sometimes converted into marble, frequently unchanged; in the latter case, exhibiting on their weathered exteriors the remains of those organisms which give at once the clue to the conditions accompanying the deposition of their parent stratum. It is with special reference to these limestone fragments that this note has been written and particularly to those occurring in one vent—the well-known “Rock and Spindle”—a mile and a half to the east of St. Andrews.