The American Naturalist. [Vol. XXVII, 
734; North America During Cambrian Time, 734; Lower Silurian 
Brachiopoda of Minnesota, 735; Recent Volcanic Eruptions in Cali- 
fornia, 818; Continental Problems, 816; Mineral Resources of the 
United States for 1891, 816; Notes on Upper Devonian Fishes from 
Canada, 817; The Diatomaceae of the Triassic (?) Sandstone of New 
Jersey, 817; Do Glaciers Excavate? 818; Plistocene Deposits of Rus- 
sia, 819; A New Plistocene Sabre-Tooth, 896; The Laurentian of the 
Ottawa District, 996 ; Relations of the Laurentian and Huronian Rocks 
North of Lake Huron, 996; The Carboniferous Glaciers of Central 
France, 997 ; Quicksilver Ore Deposits, 998; The Discovery of Mio- 
cene Amphisbaenians, 988; On Symmorium and the Position of the 
Cladodont Sharks, 999; Mud Avalanches in the Mustagh Mountains, 
82; Cladodont Sharks of the Cleveland Shale, 1083; The Neocene 
Sierra aoe 1084; Geological News, 37, 149, 270, 471, 560, 662, 
Minera S Petrography.—The Origin and ae of Igneus Rocks, 
; The Novaculites of Arkansas, 42; ew Occurrence of Prtiolite, 
43; Mineral Syntheses, 45, 277, 567; Lande Blowpipe Analysis 
46; The Rocks of the Thalhorn, 272; The New Jersey Eleolite- ag 
nite, 272 ; Mica a from kai ms; Rhyolites in Maryland 
and Penn., 273; The Nepheline and Lencite Rocks of Brazil, 274; 
Cecialinerschic aoe of Diopsides, 275; Hore from Hebron, 
Maine, 276; Methods and Instruments, 278; An Appendix to ‘* Gems 
of North America,” 278; Description of the New Rock Type, Mal- 
chite, 880; Petrography of Hokkaido, Japan, 880; Two Peculiar 
Rocks from Siberia, 381; An Ottrelite Bearing Conglomerate in Ver- 
mont, 382; Lithophysae in the Rocche-Rosse, 382; The Composition 
of Dune Sands of the Netherlands, 882; Quartz-Gabbro in Mary- 
d, 383; Minerals from the Diamond Fields of Brazil, 383 ; ta 
Resins 385; Isomorphism, 386; Etched Figures 6; 
chemical Reaction. 387; Miscellaneous, 387 ; The Besisgrapky at ad 
anada, 564; The Melibocus “Massiv” and its Dyke Rocks, 
; The Granites of Argentina, S. A., 565; New Edition of Rosen- 
ater Volume of Minerals, 567 ; eae Teal 567, 1093; Rock Sep- 
arations, 568; Anorthorites and Diabases from the Minnesota Shore of 
Lake Superior, 898; Volcanic Rocks of the Andes, 898; Basalts and 
Trachytes from Gough’s Island, 899; Origin of the Gneisses of Heidel- 
rg, 899; American Minerals, 901; Trachytes and Andesites of the 
Siebengebirge, 1003; Variolite Dyke in Ireland, 1003; Chemical Na- 
ture of Eruptive Rocks, 1003; Norites in the Eastern United States, 
1004; Ottrelite Conglomerate in Vermont, 1004; Chalcedony and 
other Silicious Spherulites, 1005; Danalite from Redruth, Cornwall 
1005; Mirabilite Changed to Theradite, 1006 ; The Schists of South- 
ern Berkshire, Massachusetts, 1087; The Phonolytes of the Hegan, 
1087 ; The Ricks of a-New Island off Pantelleria, 1088; Analy:es 
of Aalan Minerals, 1090; North American Minerals, 1091; Phy- 
