558 Reviews — Serpentine Rocks of S. Quebec. 



In the Rainy Lake region the Steeprock series of sediments 

 (including fossiliferous limestone) and volcanics is tentatively corre- 

 lated with the Lower Huronian. Following an interval of uplift, 

 deformation, and erosion, came the Seine series of sediments, which 

 is tentatively correlated with the Upper Huronian. Dr. Lawson's 

 memoir is of absorbing interest, and will strongly appeal to all those 

 who find a fascination in the more ancient rocks of our aged planet. 

 Aethtjr Holmes. 



VI. — Pkeliminaet Hepoet on the Serpentine and Associated Rocks 

 OF SouTHEBN QuEBEC. By JoHN A. Dresser. Gcological Survey 

 of Canada. Memoir No. 22. pp. viii + 103, with 2 folding 

 maps. 1913. 

 rPHE serpentine belt consists of a series of basic igneous rocks 

 JL intrusive through sedimentary rocks of Palaeozoic age. Although 

 on account of its economic importance serpentine gave its name to the 

 belt, it is actually the least abundant of the principal rocks of the 

 series. It is of two types, in the one resulting from the alteration of 

 peridotite and in the other of pyroxenite, but both were members of 

 a series of intrusive rocks differentiated from a single magma. The 

 belt includes two minerals of great economic importance — asbestos and 

 chromite. The asbestos, which is mineralogically chrysotile, is of two 

 kinds, one, which is found in veins, being longer, stronger, and more 

 valuable than the other, which occurs parallel to the cleavage of the 

 rock. The mines are by far the largest of the kind ever worked, and 

 provide at the present time about 90 per cent of the world's supply, the 

 annual production amounting to about £5(i0,000. Chromite is shipped 

 mainly to the United States, where it is used in the manufacture of 

 bichromates for use in dyeing textiles and tanning leather, for pigments 

 used in printing and painting, in making chrome steel, and in lower 

 grades for lining furnaces. Among the other minerals found are 

 chalcopyrite, pyrite, stibnite and other antimony minerals, platinum 

 (in minute amount), diamond (in crystals of good quality, but far too 

 tiny for gem purposes), vesuvianite, and magnetite. 



YII. — PAL.S0Z0IC Cieeipedes from Sweden. 

 Om Svenska Silitroirripedee. Af JoH. Che. Mobeeg. Lunds 

 Universitets Arsskrift, n.f., Afd. 2, Bd. 11, No. 1. Kgl. 

 Fysiografiska Sallskapets Handlingar, n.f., Bd. 26, No. 1. pp. 20, 

 2 pis. July, 1914. 



THIS interesting paper does not deal with the Silurian (sensu lato) 

 cirripedes of Sweden, but only with some of them, the inception 

 of the work being due to a recent discovery of cirripedes in the 

 Black Trinucleus Shales near Ullnas in Ostrogothia, which led to 

 a comparison with material that had accumulated from the same 

 beds in Dalecarlia. The three new species described are all from 

 the Black Trinucleus Shales, but figures are also given of a possible 

 Plumulites from the Colonus Shales of Scania, a doubtful Tiirrilepas 

 from the Leptsena Limestone of Dalecarlia, and a plate from the 

 Silurian of Gotland assigned to Turrilepas ivrightiana. 



