Rocks rich in magnesium are abundantly developed in a certain few areas of the world, whereas they are rare or absent in the remaining areas. With reference to the abundance of magnesian rocks in Southern India, for example, Holland has stated:—

Dr. Arthur Holmes has laid all petrographers under a debt of gratitude for his Nomenclature of Petrology, which worthily succeeds and replaces Löwinson-Lessing's Lexique Pétrographique. It represents an enormous amount of patient labour, and will provide an indispensable instrument of petrographic research. Its perusal has led the writer to consider several points in modern petrographic nomenclature which seem to need further discussion.

The tooth, of which a photograph (half-size) is reproduced, was found during Easter, 1916, by the late Mr. W. Harrison, of Selly Oak, Birmingham, who kindly lent it to the writer. Though similar finds are fairly common, this tooth by its form is of rather special interest, and so the writer thinks merits description.

During the last two and a half years I have been engaged in the study of the Cornish Veinstones in the field and in the laboratory by microscopic and other methods, and have come to the following conclusions:—

Some remarks made at a meeting of the Cornish Institute of Engineers by Dr. R. H. Rastall directed attention to the possibility of platinum being found in the Lizard. In a paper upon “Ore Deposits of Igneous Origin”, Dr. Rastall pointed out that in the Lizard the local characteristics were favourable to the presence of platinum, although no definite information of its occurrence had been reported. Much interest was aroused locally by these remarks, and the writers resolved to investigate the alluvials derived from the altered ultrabasic igneous rocks of the Lizard Group.