3. _Highly altered basic Tuffs, and agglomerates_ (calcareous chloritic schists).--Only one stump now remains. 4. _Altered Rhyolites and Dacites._--Only fragments of this rock have been revealed during Mr. Gowland's excavations in 1901. At one time doubtless there was a whole upright of this material, but its striking appearance and fracture has probably led to its demolition by generations of _souvenir_ hunters. Other fragments have been found in the barrows once within sight of Stonehenge, but now destroyed by cultivation. 5. _Sandstones, Grits, and Quartzites._--The "Altar-Stone" belongs to this class. It is interesting to note that Professor Maskelyne has pointed out the similarity between the Altar Stone at Stonehenge, and the "Stone of Destiny" in the Coronation Chair at Westminster Abbey. 6. _Grey Wackes._--Fragments only of these stones have been discovered among the chippings incidental to the dressing of the stones before erection. Their absence at the present day is not a matter for surprise, as stones of this class weather badly, and when exposed to the action of frost and cold rapidly disintegrate. 7. _Argillaceous Flagstones and Slates._--As in the case of the Grey Wackes, fragments only of these stones exist to tell the story of the uprights which have vanished under atmospheric changes. 8. _Glanconitic Sandstone_ (possibly Upper Greensand?).--Traces of this rock have been discovered at Stonehenge by Mr. Cunnington. Professor Judd suggests the possibility of a boulder of this material having been found and used by the builders of Stonehenge. 9. _Flints._--These of course are naturally found in abundance throughout the district. Most of those found within Stonehenge are broken fragments struck off in the process of repointing flint chisels during the erection of the circle.