Field investigations of pegmatites near Kragerø have been carried out for several seasons; but most of the work was done in the summer of 1935 by grants given to me by the Fritjof Nansen Fund. Some of these pegmatites had not been mined for many years and it was often very difficult, therefore, to collect complete series of the minerals. The description of the minerals of some of the dikes has therefore partly been based on a study of representive samples in the collections of the mineralogical museum in Oslo. Since some of these minerals have been bought from mineral dealers I have been very careful only to use the material whose origin seemed to be quite sure. For the photographs I am indebted to Miss Lily Monsen.