The accompanying map is the outcome of a survey of Shetland, conducted during part of several summers.

Almost the whole of the junctions laid down were visited by myself ; for the few that were not, and also for certain of the lines continued inland—which from an almost unbroken covering of peat and turf, are more or less conjectural—I am indebted to Dr. Hibbert's narrative.

To Professor Geikie's map of Scotland I am indebted for the southern limit of the isolated mass of sandstone of the Lerwick district.

Referring to my notes in number 3 of the Mineralogical Magazine for 1877, I observe one or two little matters which I hoped the march of time would improve. One desideratum, a good hotel, the Hotel d'Anniviers, has been established at Vissoie, and M. Monnet, the landlord, is a man of intelligence, and, without pretending to scientific lore, has much information concerning the mining, geology, botany and history of the neigbbouring valleys. Jean Martin, my guide in many a tough scramble, has married, and established a small restaurant with a couple of bedrooms at Vissoie, which place may now fairly be said to have become a centre for many interesting excursions ; as, to the Bella Tola, whence the panorama is very grand,—to the Cols leading from the Grimenz Thal to the Val de l' Arolla and Evolena, and also to the Turtman Thal, and so across to St. Niklaus in the Zermatt valley.

The Iron Crystals described by Mr. Beardsley in the present volume of the Mineralogical Magazine (p. 223) exhibit the remarkable structure illustrated in figs. 1 to 5, plate VII. Fig. 1 represents the crystals drawn natural size, and fig. 2 is a section of one of them in a plane parallel to a face of the cube—shewing the structure developed by etching. Figs 3 and 4 illustrate other modificatious of structure which have been observed in iron crystals, and for which I am indebted to Dr. C. O. Trechmann of Hartlepool, and fig 5 may perhaps indicate the ultimate molecular structure.