The gneissic rocks of the east coast of Hudson’s Bay have been described in my reports for 1875 and 1877, and those of Hudson’s Straits in the report for 1884. Dr. Frans Boas, in the course of his explorations has made some notes on the fundamental rocks of Baffin Land, which stretches from Hudson’s Straits northward through twelve degrees of latitude, or to Lancaster Sound. At page 57 of his report (Dr. A. Petermann’s Mitteilungen aus Justus Perthes Geographischer Anstalt, Nr. 80. Gotha. Nov. 1885), he says: “Let us, in conclusion, cast a glance on the geological structure of the last mentioned territory (the northern part of Baffin Land). The nucleus of the mountain masses appears to be everywhere gneiss, which I found especially at Kinguait and Panguirtung. In closest combination with the gneiss, granite, also occurs, which, especially large-grained, appears in the coast ranges and islands.—Anarmtung and Nuvakdjuak in Cumberland Sound; Padloping, Kexertaxdjuin, Nudlung, Tupirbikdjawitjung and Siorartijung on Davis Strait.” [Sidenote: Cumberland Sound.] “In Cumberland Sound, as well as in the Naguimiut plateau, which latter is mostly composed of fine-grained granites, there are found at isolated places, diorites and trap-granulites which have broken through the granite. The occurrence of these to the south on Blunt peninsula, has been confirmed. In Cumberland Sound I found them at Panguirtung and in a well-marked dyke in Akuliaxling eastward from Kexerten. The same diorite appears also in the mountain Kaliugujang to the east of Kinguait.” [Sidenote: Rocks of other northern localities.] “The Silurian limestones, overlying the old crystalline rocks, have been already mentioned. The same are found besides in Field Bay, and they compose nearly the whole northern coast of Baffin Land. Hall found sandstone at Lock’s Land, which perhaps belongs to the Carboniferous formation. It is said to resemble that found by Parry at Antridge Bay (Fury and Hecla Strait). Here may also be mentioned the samples of sandstone found by Bessils at Point Garry. From accounts by Captain Walker of the ship “Erik,” coal is found in loose boulders in a stream at Eclipse Sound and on Aggidjeu (Durban Island).” [Sidenote: Characters of gneisses.] [Sidenote: Useful minerals.]