The rocks described by Mr. Davies in Notes 15–20 belong to the newer series, and were collected as nearly as possible at the points indicated in the sections. They are here described for comparison with the older rocks already referred to, and with the rocks to be further mentioned to the east of this line. I selected intentionally for examination those which appeared most highly altered, or otherwise to have any resemblance to the old rocks; as it is well known that Prof. Nicol considered them to belong to that series, and not to the newer groups. The petrological evidence as given by Mr. Davies proves that they are in no way allied to the gneiss rocks of the old formation, and that they are not sufficiently metamorphosed to be allied to any schists of known Pre-Cambrian age in these areas. These facts, combined with the physical evidence of the discordance in strike also almost everywhere apparent, seem therefore conclusively to prove that they cannot be of Pre-Cambrian age, but that they belong to a much younger series, and overlie the limestone group found along the west side of Glen Laggan.