Helvine and genthelvite are recorded for the first time in Britain; of the former, three occurrences in Cornwall and one in Devon, and of the latter, one occurrence in Cornwall, are described. British danalite has hitherto been represented by two old specimens with the vague locality ‘Redruth’, Cornwall; occurrences at four Cornish localities are described, and a further Cornish locality is provided by two old specimens previously labelled as garnet. Partial chemical analyses for the helvine, genthelvite, and danalite specimens are presented; helvine and genthelvite occur in pyrometasomatic-hydrothermal deposits in metamorphosed calcareous sediments and, in one instance, in greenstone; danalite in hydrothermal deposits or lodes in metamorphosed greenstone; the parageneses of the three minerals are discussed.

This list continues the series of 21 published triennially by Dr. L. J. Spencer between 1897 and 1958. Such lists evidently meet a generally-felt need, as they now appear in the American Mineralogist, the Bulletin de la Société française de Minérlogie et de Cristallographie, and the the continuation of Dr. Spencer's series seems desirable since it differs from the others in several respects.