122 Notices of Memoirs — Dr. M. Schuster — Atmospheric Dust. 



of India. 3. Miocene (and Eocene?). Thick deposits of green and 

 red clays, with friable limestones, and salt-beds. Miocene fossils in 

 the upper horizons. 4. Cretaceous. Inoceramus-beds, marls (mostly 

 variegated), and limestones with Cretaceous fossils. Marine lime- 

 stones abounding in organic remains. 5. Jurassic and Lias. Light- 

 coloured sandstones and grit, with marine limestones, and plant- 

 remains. 6. Triassio. " Red-grit Group ;" an enormous assemblage 

 of red sandstones, conglomerates, breccias, and volcanic tuffs, with 

 intercalated eruptive rocks (mostly melaphyres), and several horizons 

 of Brachiopod limestones. 7. Permian. Green and grey schists, 

 sandstones and conglomerates, with " Boulder-beds," thin coal- 

 seams and imperfect impressions of plants S.E. of Herat and in 

 Khorassan, alternating with hard limestones, containing Brachiopods, 

 Conchifera, and Fusulinas. Nos. 5, 6, and 7 may possibly cor- 

 respond to the Gondwana Formations of India. 8. Carboniferous 

 (and Devonian?). Very thick, compact, grey limestones, with sub- 

 ordinate shales, containing Fenestella, Productus semireticulatus, 

 Athyris Eoyssyi, etc., in the upper horizons. No. 8, answering to the 

 Eailling strata of Cashmere, constitutes the lowermost horizon in 

 the large folds of the Davendar, Doshatch, Bizd, and other mountain- 

 chains. 



V. — Atmospheric Dust. By Dr. M. Schuster. Tmper. Acad. 



Vienna, Meeting 14th January, 1886. Communicated by Count 

 Marschall, F.C.G.S. 



THIS dust was collected at Klagenfurt in Carinthia, after a rain of 

 muddy substance, which had taken place on the 14th October, 

 1885. The chief constituents of the dust are minute fragmentary 

 crystalline granules and flakes of the following minerals : — quartz, 

 opal, orthoclase, biotite, phlogopite, pyroxene, amphibole, light- 

 coloured mica, talc, kaolin, chlorite, rutile, anastase, zircon, tourma- 

 line, ferruginous clay, spinel, magnetite, pyrites, magnetic pyrites, 

 calcite, magnesite, ferruginous dolomite, and apatite. The presence of 

 metallic iron could not be ascertained. The microscope showed 

 a prevalence of siliceous, silicified, and calcareous remains of organ- 

 isms, especially of Diatomaceas, either in single or in pairs, together 

 with a few carbonaceous or carbonized substances, such as the spores 

 of Fungi and such like, filaments of Algae and other plants, silicified 

 membranes of parenchymal cellules, and pyritized and silicified 

 spherules, resembling pollen. This dust bears a great general 

 resemblance to the atmospheric dusts described by Ehrenberg and 

 Silvestri. The reddish-yellow colour, which it has in common with 

 the "Passat" dust, may be an objection against its having come 

 direct from the Sahara. 



[Compare the results of Prof. Judd's examination of Nile mud, 

 Proc. Roy. Soc. vol. xxxix. No. 240, p. 216, Nov. 1885.] 



